CIHM
Microfiche
Series
(Monographs)
ICIVIH
Collection de
microfiches
(monographies)
Canadian Institute for Historical Microreproductions / Institut Canadian de microreproductions iiistoriques
Technical and Bibliographic Notes / Notes techniques et bibliographiques
The Institute has attempted to obtain the best original
r rpy available for filming. Features of this copy which
may be bibliographically unique, which may alter any of
the images in the reproduction, or which may
significantly change the usual method of filming are
checked below.
Coloured covers /
Couverture de couleur
□ Covers damaged /
Couverture endommagee
□ Covers restored and/or laminated /
Couverture restaur6e et/ou peliiculee
I I Cover title missing / Le titre de couverture manque
I I Coloured maps / Cartes g6ographiques en couleur
ry\ Coloured ink (i.e. other than blue or black) /
vlJ Encredecouleur (i.e. autre que tieueou noire) '
I /I Coloured plates and/or illustrations /
Planches et/ou illustrations en couleur
Bound with other material /
Relie avec d'autres documents
n
n
Only edition available /
Seule edition disponibie
Tight binding may cause shadows or distortion along
interior margin / La reiiure serree peut causer de
I'ombre ou de la distorsion le long de la marge
int^rieure.
Blank leaves added during restorations may appear
within the tpxt. Whenever possible, these have been
omitted from filming / Use peut que certaines pages
blanches ajout6es iors d'une restauration
apparaissent dans le texte, mais, lorsque cela etait
possible, ces pages n'ont pas 6te filmees.
""^ Additional comments /
— I Commentaires suppiementaires;
L'Institut a microfilm6 le meilleur exemplaire qu'il lui a
6t6 possible de se procurer. Les details de cet exem-
plaire qui sont peut-fetre uniques du point de vue bibli-
ographique, qui peuvent modifier une image reproduite,
ou qui peuvent exiger une modification dans la m§tho-
de normale de filmage sont indiqu6s ci-dessous.
I I Coloured pages / Pages de couleur
j I Pages damaged / Pages endommag6es
D
Pages restored and/or laminated /
Pages restaur6es et/ou pellicul6es
Q Pages discoloured, stained or foxed /
Pages d6color6es, tachetees ou piqu§es
|v7| Pages detached / Pages d6tach6es
I v/| Showthrough / Transparence
j I Quality of print varies /
D
D
D
Qualit6 inegale de rimpre?»ion
Includes supplemer; j ri?/ al/
Comprend du materio ■ ,; ji , lentaire
Pages wholly or partially ■ uied by errata slips,
tissues, etc., have been retilmed to ensure the best
possible image / Les pages totalement ou
partiellement obscurcies par un feuillet d'errata, une
pelure, etc., ont ete filmees a nouveau de fagon k
obtenir la meilleure image possible.
Opposing pages with varying colouration or
discolourations are filmed twice to ensure the best
po<=;sible image / Les pages s'opposant ayant des
colorations variables ou des decolorations sont
filmees deux fois afin d'obtenir la meilleure image
possible.
Various pagings.
This item is filmed at the reduction ratio checked below /
Ce document est filme au taux de reduction indique ci-de»sout.
lOx
14x
18x
22x
26x
30x
/
12x
16x
20x
24x
28x
32x
The copy filmed here has been reproduced thanks
to the generosity of:
Engineering Sciences Library
Queen's University
This title was microfilmed with the generous
permission of the rights holder:
Forbes Tad Rickard
L' exemplaire fllme fut reproduit grace a la
generosite de:
Engineering Sciences Library
Queen's University
Ce titre a ete microfilme avec I'aimable aulorlsation
du detenteur des droits:
Forbes Tad Ricliard
The images appearing here are the best quality
possible considering the condition and legibility of
the original copy and in keeping with the filming
contract specifications.
Original copies in printed paper covers are filmed
beginning with the front cover and ending on the
last page with a printed or illustrated impression, or
the back cover when appropriate. All other original
copies are filmed beginning on the first page with a
printed or illustrated impression, and ending on the
last page with a printed or illustrated impression.
The last recorded frame on each microfiche shall
contain the symbol -^(meaning "CONTINUED"), or
the symbol V (meaning "END"), whichever applies.
Maps, plates, charts, etc., may be filmed at
different reduction ratios. Those too large to be
entirely included in one exposure are filmed begin-
ning in the upper left hand corner, left to right and
top to bottom, as many frames as required. The
following diagrams illustrate the method:
Les images suivantes ont ete reproduites avec le
plus grand scin. compte tenu de la condition et de
la nettete de I'exemplaire filme. et en conformite
avec les conditions du contrat de filmage.
Les exemp, aires originiux dont la couverture en
papier est imprimee sont filmes en commen?ant
par le premier plat et en terminant soit par la
derniere page qui comporte une empreinte d'im-
pression : d'illustration, soit par le second plat,
selon le cas. Tous les autres exemplaires origin-
aux sont filmes en commen^ant par la premiere
page qui comporte une empreinte dimpression ou
d'illustration et en terminant par la derniere page
qui comporte une telle empreinte.
Un des symboles suivants apparaitra sur la
derniere image de chaque microfiche, selon le cas:
le symbole -> signifie "A SUIVRE", le symbole V
signifie "FIN".
Les cartes, planches, tableaux, etc., peuvent etre
filmes a des taux de reduction different?. Lorsque
le document est trop grand pour etre rcoroduit en
un seul cliche, il est filme a partir de I'angle
superieur gauche, de gauche a droite, et de haut
en bas, en prenant le nombre d 'images
necessaire. Les diagrammes suivants illustrent la
methode.
1
2
3
4
5
6
::-?=ss'*r^«i?'isaK5tamP2r^!eiiKsair^
MICROCOfY RESOIUTION TBT CHART
ANSI and ISO TEST CHART No 2!
Ui I 2.8
m
2.2
1.8
1.6
^ -APPL IED \M^!3E_ I
r-.^ WofHesr#f. Ns» York '4609 -^Jk
•■S^ -'''6)^82 CiOO r^^r.e
**^.
fe:^
^1
■ iwM
^^.l¥&.r. '^H^H
KqPhSo'IH^B
■ i ..»i^
B r'^x \bk.k^ C'^^H^^^H
'.."■i If'i"°
l:.^3fln^B^
f-Tt-ir;-:.
J*-ii^f^- •
i
7 ■■■:Zli^ -
I '
■ .' ■ . i >
|--. ,
. ■■■■"" 1 -'"■ -
fefct
; :-.iJ=&...i- '^r' :aKa^:£ -. ..
ourneY5 of
Observation
ByT.A. Rickard
Editor of the Mining and Scientific Press; formerly
Editor of the Enginekring and Mining Journal; Associate
of the Royal School of Mines; Member of the Institution of
Mining and Metallurgy; Member of the American Institute
of Mining Engineers ; State Geologist of Colorado ( 1895-1901 ) ;
Author of 'The Stamp-Milling of Gold Ores,' 'The Copper
Mines of Lake Superior,' 'Ihe Sampling and Estimation of
Ore in a Mine,' 'Pyrite Smelting," 'The Economics of Mining.'
SAN FRANCISCO
1907
Copyriuhl IQOJ
Bv :iii MfMiNS AND Sciimific P^uf
Printed br
San Franciico
T)edictttioii
TT^i
y M'/t^
^:^^^Uyi^ ^
r^if.
t ' y 1 (»
TJrefflce
Thi' book records the observations made by a
trave!«* A'ho happened to be a mining engineer; it
is supp cd to belong to the typ« ' <" voyages meiallurgi'
ques, such a? were published ir "efore the globe
had been over-run by tourists s distant corners
rendered commonplace by the -ggcrations of the
daily press. To the members of my profession the
comment concerning the industrial conditions, geo-
logical structure, mining methods, and metallurgical
practice of southwestern Colorado and a progressive
part of Mexico m\\ have the interest that comes from
observations which reflect a point of view somewhat
similar to their own, while to the layman the not too
severely technical descriptions, aided by beautiful
photographs, will afford information of a kind rarely
obtainable except in periodicals devoted to tech-
nology. It is hoped that this record of conditions in
two representative mining regions may have a his-
torical value '■ the days to come. Moreover, I have
thought it Wi o publish *his volume as an expres-
sion of thank .o those who were kind enough to
give me m :ny valuable data and to make my travels
pleasa.H hy their courtesy and hospitality. I am
inr ebtc \o many friends for the photographs, for
only a ic v of them are my own. From the United
States Geological Survey were obtained half a dozen
of the best views of the San Juan; other acknowledg-
ments appear in the text.
„ ^ . , T. A. RICKARD.
>an Francisco, Septembe. 15, 1907.
5lllnes of Mlexlco
Being the record of a journey from New
York to Mexico, together witJ a descrip-
tion of the mining industry- . F] Oro,
Pachuca, and Guanajuato, as observed in
October, 1905. Reprinted by permission
from the Mining and Scien rinc Press.
t :t * *' ;, " '~^c •"■•»,»■ ■•'ixTi^'
ISBSsr— ^sHT
Contenb
Chapter p^^^^
1. New York from the Harbor. A Farewell to Man-
hattan
2. Havr la. A Cigar Factory. The Spanish Conquest.
Hernando Cortez. The First Sight of Orizaba . 5
3. Vera Cruz. On the Mexican Railway. Tropical
Vegetation. Coffee Plantations. At Orizaba . 13
4. The Physiography of Mexico. Outlines of History.
At Esperanza. The Maguey and Pulque. A
National Habit. Arrival at the City of Mexico . 18
5. Geology Along the Railroad. Precious Metals in the
Volcanic Dust. Vein Formation. The Sulphur
of Popocatepetl ^e
6. The City of Mexico. First Impressions. The School
of Mines. Memories of Del Rio. The Meteor-
ites. Cortez 29
7. El Oro. Rich Mines. The Geology of the District.
The Mexico Mine. The Structure of the Lodes.
In the El Oro Mine. A Wide Lode-Channel.
Faults .-
8. Geology of the Esperanza Mine. Interesting Struc-
ture. A Big Fault. Rich Orebody. Story of
the Discovery. Character of the Ore ... 43
9. Development of the Milling Practice at El Oro. Be-
ginning of Cyanidation. First Big Mill. Change
of Method. Tube-Mills and Re-Grinding . . 54
10. Treatment of Slime. Use of Lead Acetate. Addi-
tion of Lime. Its Double Function. Settlement
of the Slime. The Tube-Mills. Their Lining.
Successful Work 5j
tx
CONTENTS
Chapter Page
11. Further Notes on El Oro Practice. The Stamp-Mill.
Mortars and Guides. Apparatus for Sizing. The
Precipitation House. Filter-Presses. Record of
Tests 69
12. The Mill of the Esperanza. Use of iluntington Mills.
Treatment of Sand. No Amalgamation. Extrac-
tion 76
13. Mining Methods in the El Oro Mine, riiamond-
Drilling in the Esperanza. Timbering Bad
Ground. Precautions Taken. Laying of 1'rack.
Excellent System "9
14. Taxes. The Dynamite Imposition. Electric Power.
Dos Estrellas. It? Discovery. The Humor of
Cyaniding. How Boundary Marks Are Pre-
served 93
15. ^line Labor. The Contract System. Native Improv-
idence and Skill. Difference of Locality. Poor
Hammermen, but Willing Workers. Hot Mines loi
16. Pachuca. An Old Mining Centre. Ancient Methods.
The Discovery of the Patio Process. Revolu-
tionary Days. The Invasion of the Moderns . . 109
17. Real Del Monte. Old Machinery. The Viscaina
Lode. Its Early Romance. La Difficultad. An
Electrical Pump. Lode Structure. Local Ge-
ology. Scenery 117
18. The Reduction Works of Pachuca. The Hacienda de
Guadalupe. Treatment on the Patiu. A Metal-
lurgical Survival. Some Criticisms .... 129
19. The Chemistry of the Patio Process. Chemical
Equations. Observations of Humboldt. Loss of
Mercury. Contrast of Policy 139
X
•'f-F^i'^-'^aa^.f^S"
^■■w.^'j:-ijfsmi:-^^iMRimkw^
CONTENTS
f
1
i3
Chapter Page
20. Other Metallurgical Processes. The Hacienda la
Union. Kroencke's Method. Tube-Mills. The
Barrel Process. Francke's Process. Chilean
Mills. Retorting the Am gam. The Planilia . 148
21. First Glimpse of Guanajuato. The History of Local
Mining. The Veta Madre, and Its Bonanzas.
Rich Mine-Owners. The Count of Valenciara.
Story of the Church. Decadence of the Dis: ot 160
22. Guanajuato at Its Height. Deep Mining. Visit of
Humboldt. Decadence. La Luz. The Revival.
\ii American Invasion. The Story of Modern
Progress 169
2.3. Visit to the Old Mines. A Cavalcade. The Bustos
Plant. Mechanic?! Devices Against Manual
Labor. The Mother Lode. San Miguel de
Rayas 176
24. A Grand View. Reminders of a Former Time. Eng-
lish Enterprise 184
25. The Great Shafts of the Veta Madre. The Rayas.
The Cata. The Tiro General. What Bryan Said
of It. How It Was Unwatered. A Wonderful
Spectacle 188
26. The Malacate and Its Operation. The Avio System.
Electric Power. A Curious Difficulty. How the
Eagles Interrupt the Current. A Strike . . 196
2y. The Peregrina Mine. Old Spanish Workings.
Shrines Underground. Acetylene Lamps. Sam-
pling a Dump 201
28. The Dumps of Guanajuato. How to Sample. The
Mexican Idea. Two True Stories. The Biter
Bit 2.
xi
WGm^^Kmf:it2iS:'im^K^'3^f^m^m^B^ii^
CONTENTS
Chapter
29.
30.
Page
The Geology of the Veta Madre. A Big Fan' Posi-
tion of the Orebodies. A Cross-Section. Hum-
boldt's Description. What is a True Vein? . .211
The Development of Metallurgical Practice at the
Sirena Mill. From Amalgamation to Cyanida-
tion. Re-Grinding 229
31. Method of Treatment in the Bustos Mill. Conveying
the Tailing by Pipe. The Stamp-Mill. Cyanide
Practice. Comparison with the Patio Process
12. Old Methods. An Abandoned Arrastre. The Ha-
cienda de Rocha. Men and Mules . .
33- The Flood at Guanajuato. The Humor and the
Tragedy of It. Conclusion 252
239
246
xu
tut of miustratlons
The Gateway Frontispiece
Map of Mexico FacingPage
On the East River, New York . . 2
New York, as Seen from the Harbor .......
The Morro, Havana. Making Drawn- Work i-i Mexico '. 4
Central Park and Albesu Theatre, Havana ] 5
The Harbor of Havana 6
Cabaiias Castle, Opposite Havana ' ,
A Glimpse of Old Havana 10
The Prado, Havana . . 11
Orizaba
On the Railroad above Maltrata j.
Tropical Vegetation 14
A Coffee Plantation ! ! is
A Maguey Plantation 20
The Patio of the Iturbide. The Plaza at Orizata ! '. .21
The Palace of Chapultepec . 22
The Chii-ch of Guadalupe .2^
A Country House in Mexico 26
Popocatepetl
A Fruit Vendor • • i ' . ! 28
On the Presa at Guanajuato. A Glimpse of Chapultepec '. 29
The Casa Blanca, at El Oro
The Timber Camp of the El Oro Mining and Railway Co 3 s
Statue to the Last of the Aztec Kings ^5
Sorting Ore. On the Outskirts of Guanajuato 4.:
Putting Timbers in Place ' ^5
A Good Lode in the El Oro Mire ........ aj
xiii
-a_-
'^^,:-m.^i.':r'^.-
LIST OF ILLUSTRATIONS
Facing Page
A Rich Stope in the Esperanza Mine 52
General View of El Oro S3
In the Market Place ^
Another Market Place ^'
Cyanide Vats and Tailing- Wheel 68
Interior of the El Oro Stamp-Mill 69
Leaching- Vats of the El Oro Mill 76
Blaisdell Excavator and Sand- Vats 17
Timbering in the El Oro Mine. An Old Water-Carrier . . 84
Electrical Traction Underground in the Esperanza Mine . 85
Timbering a Drift-Stope in the El Oro Mine 85
General \'iew of El Oro 92
The Esperanza Mine and Mill 93
The Water-Carrier or Botero 9^
The Cross near the Somera Shaft 99
Pay-Day at the Casa Blanca, El Oro 99
General View of Pachuca "°
The Plaza of Pachuca m
The Mines of Pachuca "-^
The Mines of Pachuca "9
An Old Patio in Action '22
A Chilean Mill in Operation 123
El Camonero. Moving Slime onto the Patio 134
A Tube-Mill in the Hacienda La Union at Pachuca . . .134
Two Views of the Patio Process '35
Three Stages in the Patio Process 138
Horses Treading the Charge. El Camonero I39
A Typical Patio '46
Mixing the Charge on the Patio I47
Furnace for Retorting Amalgam 'S^
Two Views of Men Operating the Planilla at Pachuca . .159
The Flying Buttresses of San Miguel de Rayas .... 166
In the Courtyard of the Rayas Mine 167
Looking Down the Main Street of Guanajuato . . . 170
xiv
LIST OF ILLUSTRATIONS
Facing Page
The City of Guanajuato 171
Among Friends at Guanajuato 176
Steel Ore-Bins and Battery Foundations of the Bustos Mill . 177
The Gateway of the Rayas Mine 178
The Ruins of the San Miguel de Rayas Mine .... 179
The Great Shaft of the Valenciana, Looking Down . . . 190
Bridge over the Guanajuato River, near La Presa . .191
Two Views of the Tiro General 192
The Tiro General or Valenciana Shaft 193
A Malacate or Horse-Whim 196
On the Road to the Mines 197
A Bit of Old Mexico 198
A Distant View of Guanajuato. The Villas of the Presa . 199
The Basket Store. By the Way 202
Shrine in the Peregrina Mine 203
Hacienda San Francisco de Pastita 203
A Big Slope in the Peregrina Min,. 204
Sorting Ore at the Peregrina Mine 205
Guanajuato 212
A Typical Street in Guanajuato 213
A Bit of the Veta Madre 220
A Mexican Ox Wagon 221
The Tanateros. On the Street 228
Mexican Miners at Work 229
The Hacienda San Francisco de Pastita 236
A Glimpse of Guanajuato Through a Hedge of Organ Cactus 237
Pipe-Line for Conveying Tailirf. Tube-Mill at Pachuca . 242
A Mexican Family 243
Water Wheel and Irrigation Method 246
An Old Arrastre 247
Hacienda de Rocha 250
T)T)ical Hacienda de Beneficio or Reduction Works . . .251
Scenes in Guanajuato After the Flood 254
Plazuela de San Pedro, Guanajuato 255
XV
i
TCul of TOrawlttjjs
Figure Page
1. Cross-Section Through Shaft of the Mexico Mine . 37
2. Cross-Section of Vein in the Mexico Mine . ■ • 39
3. Diagram Showing the Series of Geological Events 45
4. Lode-Fault, San Rafael Vein 47
5. The Esperanza Fault. After J. E. Spurr .... 49
6. Plan of Second Level of Esperanza Mine .... 51
7. Diagram of Cyanide Treatment at Plant No. 2 . . 57
8. Diagram of Sizing Tests at Mill No. 2 .... 74
9. Drift Timbering 82
10. Timbering in Bad Ground 83
11. Use of Jack- Screw 83
12. Special Shaft Set ; 14-in. Timbers 85
13. Square Set. 8-in. Timbers. Plan and Elevation . . 86
14. Square Set. 8-in. Timbers. Elevation and Details 87
15. Split Switch, for Electric Motor Underground . . 90
16. Fixed Switch in Track Underground 91
17. The Santa Inez Vein 125
18. Cross-Section of the Veta Madre 212
19. C. s-Fault of the Veta Madre 213
20. Plan and Sections of the Veta Madre 215
21. Typical Section of the Veta Madre 218
22. Arrangement of Classifiers 233
23. Old Stamp-Mill 248
24 and 25. Arrastre and Pans 249
26 and 27. Retorting the Amalgam 251
XVI
^CW#' .
3W8%JTT * -«r£'^^^F5"«Er'r^:i^'Tt5^iw^
/
^ftllnes of !Jtt exlco
Chapter t
NEW YORK FROM THE HARBOR — A FAREWELL
TO MANHATTAN.
HE tide was sweeping
down the channel as the
Seguranfa left her berth at
the Brooklyn wharf and
swung into the East river.
It was a clear sunny morn-
ing early in October and
the great harbor of New
York lor. .:d its very best.
«^ ^^ - - To the sound of many
whistles our steamship threaded her way among the
ferry-boats and barges that congregate where, off
Governor's island, the estuary separating Long
island from Manhattan meets the waters of 1'ie
Hudson. As we passed between Fort William and
the statue of Liberty, the broken sky-line of New
York City stood silhouetted against the sky. There
,if.va^^^^mmii^r^
aTi«'»^
AMONG THE MIXES OF MEXICO
was just enough smoke to soften the outlines of the
serrated pile of lofty buildings, which, like a Titan's
stronghold, guard the great waterway. Knowing
the manifold activities that have created the island
city, I felt the impressiveness, rather than the poetry,
of the scene. Even such smoke as came from the tall
towers of steel and stone, called, with grim humor,
the 'sky-scrapers,' seemed, not the incense rising from
a peaceful dwelling, but the murk of battle, the con-
fused black fog of complex strife. Despite her higher
mental activities and benevolent endeavors. New
York, rising proudly by the waters that made her a
great seaport, is the expression in stone of a relent-
less materialism, a predatory finance, and a reckless
luxury of life. Even the statue of Liberty, with her
bronze oxidized to green and her guano-crowned
head, has the air more of an old woman holding aloft
a hot penny to incite a scramble among the awaiting
small boys, than of the representative of a freedom
long since changed to license.
As the Seguranga turned into mid-channel we
could see the dark canon of Broadway and the series
of splendid structures that line its sunless depth.
Trinity church is no longer to be seen, it is obscured
by a 23-story sky-scraper where congregate daily a
group of men capable of running a continent — and
they do their best. The financiers look down upon,
and over, the spire of Trinity — in more senses than
one. When Huxley came to America, in 1876, he,
like all visitors, was impressed with the scene pre-
1
NEW YORK HARBOR 3
sented even by the undeveloped New York of that
day, and seeing the yellow dome of the World build-
mg, which for so long dominated the high roofs of
the aty he exclaimed that in approaching the shores
of other lands, the first thing to be seen was a church-
steeple, but that here, emblematic of the unshackled
thought of a new country, the first to catch the eye
was the tower of a newspaper. If he had only known
for what literary sewage that yellow dome stood
sentry, he, though an agnostic, would have longed to
see the old-fashioned landmark. Trinity steeple is
dwarfed by the Empire building, but, in compensation,
the dome of the World building is hidden by several
recent monuments to the growth of our steel in-
its tht '^V'7 '' ^f '" ""^ '^^^'' ^'•°^'"& dim amid
Brnnwf K . '""^ u'' '^' '"""^^''^^ ^^ ^^e crowds at
Brooklyn bridge, the foul air of the Subway the
.s and, the .hi.e hulls of the battleships at anchor off
th. rio'*^'' '"'" P'"'^*' of ^ handsome yacht,
he ^ low processmn of barges crossing to Brooklyn
the stately sadmg ships preparing fori long voyage
and the majestic movement of a huge Atlantic fee;
throbbmg hfe, the pulsations of which are felt the
world over. And so. farewell, thou Empress City o
4 AMONG THE MINES OF MEXICO
the New World, thou hast the respect received by
those that have power, and the admiration due to
those that are magnificent; if thou dost not win the
love awakened by kindly deeds and homely service,
thou reckest not. Men may come and men may go,
as long as steel is strong and gold is good !
#
l*L M
1
c
"^VJL:
9
copter 2
HAVANA— A CIGAR FACTORY— THE SPANISH CON-
QUEST— HERNANDO CORTEZ— THE FIRST SIGHT
OF ORIZABA.
T was four days to Havana.
The port is guarded by the
Morro, a castellated fort stand-
ing on a promontory to tht left
of the entrance. During the late
Spanish-American war, Morro
castle was often busy, but it diH
no execution until the last da> ,
in fact, after the armistice had been signed at Porto
Rico. On that soHtary occasion a shell went through
the New Orleans, a cruiser, from stern to bow, between
decks, killing no one, but playing sad havoc with the
officers' quarters. Within the harbor, one is still
reminded of the late unpleasantness by the remains
of the sunken battleship Maine. The military mast
and a portion of the 'strong-backs,' or iron super-
structure, project above the water. To them I saw
attached a metallic wreath on which was inscribed
M^mori Missouri, evidently placed there by the men of
another battleship. The Maine was blown up on Feb-
ruary 16, 1898, and I recollect the stir it made in dis-
tant lands, for on that day I happened to be at Cairo,
Egypt, where everyone in the Anglo-American col-
ra
M
T^
-arti-:^7-=3:j-^.<
TZZ^
:T>
6 AMONG THE MINES OF MEXICO
ony confidently accepted the tragedy as the fore-
runner of war. There have been many discussions as
to the responsibility for the crime, but it is generally
accepted among the well-informed that it rests upon
the 'partidc revolucionario, the revolutionary party in
Cuba, whose object it was to embroil the United
States in war with the Spanish Government. How
well they succeeded, all the world knows.
I shall not try to give any account of Cuba, even
at second hand, for is it not told, and told well, by
Robert T. Hill, whose 'Cuba and Porto Rico,' is a
monument to his insight and industry. Cuba is a lovely
island, about the size of New York State, covered by
good soil and possessing a wonderful variety of eco-
nomic resources. Only 10 per cent of the island is
cultivated; in the valleys of the western hill-country
is grown the tobacco that has done so much to soothe
mankind, to express the courtesy of the civilized, and
to promote the 'riendship of the thoughtful. Natu-
rally, I went to a cigar factory and bought some real
Havana cigars on the spot, fresh from the making.
In a large rooiu about a hundred men sat in rows
before small tables, like school-boys' desks. They
were wrapping the tobacco leaf into cigar form. As
they worked, a man standing on a stool read to them
from the daily paper; he read dramatically and well,
the purpose being to keep th» workers interested.
The proprietors of such estabMshments encourage
this practice, which is general, because the men do
not talk while the reading proceeds. When a Span-
a;^
u
■r.
SANITATION AT HAVANA 7
jard talks he uses his hands in gesture, hence he can
not employ them in labor; therefore the reading en-
courages efficiency. The men pay 10 cents per week
from their wages ($J per day) to the reader, who, in
large establishments, makes as much as $125 per
month.
Most travelers have spoken of the unhealthiness
of Havana, of the dirt and filth that force their contrast
with its beauty and color. Whatever criticism may
be passed, by an unfriendly historian, on the Ameri-
can interference with Cuban aflfairs, it is certain that
the sanitary measures undertaken after the war have
wrought wonderful improvement. Garcia, Palma,
even Sampson and Schley, were great men, but
greater than these were George Waring and Leon-
ard Wood, who did more for civilization than the
leaders of war. And theirs was a contest with dan-
gers as great as co.. . to those on the battlefield, for
Waring died, the victim of the yellow fever that he
almost eradicated.
But Havana interested me most as a link in the
story of Spanish conquest. Hernando Cortez, after
outfitting at Santiago, called at the port of Havana
before starting upon his great quest, on Frhruary 10,
1519. His fleet consisted of eleven vessels, more than
half of them open brigantines, and the biggest not to
be rated at over 100 tons. Thence he went to the
coast of Yucatan, making a halt at the island of
Cozumel, before proceeding to the mainland of
Mexico. He landed at Vera Cruz on April 21. We
t AMONG THE MINES OF MEXICO
followed nearly in this course, for from Havana we
went to Progreso. the port of Menda, which is the
chief Jty of Yucatan, and from there we also went
to Vera Cruz-as did Cortez-on our way to Mexico
City The parallel served to emphasize the differ-
ence Cortez and his buccaneers went through un-
charted seas and to a land they knew only by rumor;
to them the West was full of an unlocked mystery
and the place of untold gold; to us there was keen
interest and expectation also, but it was an mterest
toned by experience and an expectation limited by
knowledge. However, even the conquistadores can
have had no more discomfort or have used language
more picturesque than the passengers of the
Seguran^a when we lay ofi Progreso for three days at
the mercy of a 'norther,' or north wind, which pre-
vented the captain from unloading his cargo or com-
ing to anchor. Progreso is an open roadstead, and
when the north wind bio--, the Irhters that tranship
the cargo of the larger steamers are afraid to leave
the shelter of the wharf; hence wearisome delays
such as ours. And when the sea calmed it was pain-
ful to watch the uninttlligent manner in which un-
loading proceeded. Among other consignments
there was one of 40,000 bricks; the passengers, eager
to see the steamer on her way, watching the wretched
peones removing this cargo from the hold, s'.ffered
with an impatience only to be surpassed by the mor-
tification of the consignee, who must have paid
heavily for his bricks only to receive them m a badly
HiM
IMl
MINING IN CUBA
battered conditjon. Don't ship brick from New York
to Yucatan!
Between New York and Vera Cruz we saw no
mines; nevertheless, it will be interesting to refer to
certain facts of history. The first of these islands
(afterward called the West Indies) to be colonized
was Hispaniola, subsequently known as Hayti and
Santo Domingo. The great admiral, Columbus, had
discovered it in 1492 and it was he that named it
'Little Spain.' At Isabella and Santo Domingo were
founded the first settlements maoe by Europeans in
the New World. Hispaniola was rich in gold, for
the early records make frequent mention of the
mines; these were the Buena Ventura placers and
other diggings in the Cibao region where the forced
labor of natives was employed, often in a cruel man-
ner, to wash the gravel. Spanish estimates of the
production — according to my friend, F. Lynwood
Garrison — range from $200,000 to a million dollars
per annum during the first quarter of the sixteenth
century. The chief mining towns were Cotui and La
Vega ; as far as can be judged, the gold came chiefly
from the erosion of small stringers in the diorite of
the Cibao range.
It was the impoverishment of these mines that
led to the colonization of Cuba. This island had been
named Juana, and then Fernandina, but the Indian
name has survived all the Spanish christenings.
Cortez was a member of the expedition sent by
Velasquez, the governor of Hispaniola, to conquer
w
lO
AMONG THE MINES OF MEXICO
Cuba, in 1511. Subsequently, but before he invaded
Mexico, he was one of those that secured an estate
there, living on his plantation and introducing some
of the first of the cattle that were brought to Cuba.
It is interesting to note that Cortez settled at St.
Jago, a name since corrupted to Santiago. He is
said to have worked for gold within his domain, the
deposits promising better than those of Hispaniola.
But Cuba never produced much gold; it is true that
the first Spaniards found the natives in possession
of personal ornaments made of gold, but these repre-
sented the metal gathered in small quantity and dur-
ing a long period. The extermination of the aborigi-
nes prevented their tyrants from learning anything
about the source of the metal. Since that day Cuba
has won a position as a mineral region, but this is due
to her deposits of iron and manganese, together with
those of copper, which occur within a few miles of
Santiago, where Cortez was alcalde. Across the bay,
in the mountains of Cobre, are the ancient mines
whence the great conquistador derived both his gold
and copper. The development of these deposits has
been revived since the Spanish-American war and it
is to be hoped that they will become the basis of
steady industry.
At last, three days overdue, we arrived within
sight of the Mexican mainland. It was a sunny morn-
ing, with a breeze raising white caps on the sea and
moving masses of cloud from off the dark bank on the
western horizon that marked the land of the Aztecs.
FIRST SIGHT OF ORIZABA „
Clouds obscured the view, mountains loomed to the
no th.^rd. and among them the gleam of snow;
ver cT \'"" '^°"' ^" *^^ "hite building
of V era Cruz makmg a brilliant fringe along the
here. But there was no sight of Orizaba, the vol
he fl T^T";^''^^ '''' ^'^'^' -hich rises from
the flats behmd Vera Cruz and forms a great land
mark m th,s part of Mexico. Borrowing a tel s ope
1 could d.stmguish. over the dancing blue waves the
yellow strand of St. Juan de Ulua and behTndk the
Cruz. The white wmgs of fishing boats came into
he picture, and northward foreft-clad mountl^s
TnoJ^TtJ' '''"'' °' '"'^ ^"'"'"'^^ crested whh
••^M^l
^^
12
AMONG THE MINES OF MEXICO
or inspired a poet. It seemed so high a1 all
meaner things, rising sheer from the sea, t .iter-
vening flat layers of mist emphasizing the height,
while the brilliant sunlight upon the snowfields made
it appear closer than the lowlands at the base. In a
way, it reminded me of my first view of the Southern
Alps of New Zealand, as seen one morning on board
ship coming from Tasmania, when the serrated peaks
flanked by pine forests rose above the troublous dark
green waves following in the wake of a storm. But
in that picture there was a series of high crests; here,
there was one in solitary grandeur and without a
peer. Scenes such as these compensate for the dis-
comforts of travel and afford a stock of impressions
from which one can draw on dark days and in restful
hours, when the mem.ory harks back to the past, as
to the refrain of some sweet song.
;-.:k" '•'i".,-"' -:^rM\: ^-^ — Ti ■' ■ '-: e^y'^'cCryfJ
(ri)apUr 3
VERA CRUZ — ON THE MEXICAN RAILWAY —
Tr.OPICAI VEGETATION— COFFEE PLANTATIONS—
AT ORIZABA.
ERA CRUZ is not the dirty city
it used to be; the streets are
cleaner than formerly, and the
erection of new wharves and
quays gives the incoming trav-
eler an excellent impression. But
the back streets and by-ways are
not salubrious, nor does the ever
present buzzard suggest pleasant imaginings. These
hideous carrion birds are seen everywhere, flopping
about in the streets, perched on roofs, even dominat-
ing telegraph poles; nay, their foul black shapes ob-
scure the blue canopy and desecrate the majesty of
Orizaba.
If you arrive in the morning on the way to Mexico
City, you can leave Vera Cruz in the afternoon, so
as to reach the town of Orizaba by dinner time. In
this way, escaping from the coast and going to an
altitude of 4,000 feet, the traveler avoids the risk of the
calentura, the fever of the tropical lowlands. The
journey on the Mexican Railway is one of the won-
ders of the world, in respect of scenic beauty and
variety of vegetation. At first the train winds
14
AMONG THE MINES OF MEXICO
throush sandhills, partly hidden by abundant -revn,
and then over marshy ground; but this is only f jr ten
miles, when the ascent begins, over the lower plains.
Sugar and corn appear; th?n comes a grass country
interspersed with scrub and cactus, much like Natal,
only the cactus here is in greater variety and instead
of anthills the surface is dotted with boulders of dark
lava.
The train threads its way through rank grass and
past frequent hedges of organ cactus ; the scars made
by the railroad, even the steepest banks, are entirely
healed with verdure. When the locomotive stopped
we heard the broken notes of the orache and there was
further confirmation of the plentiful bird-life, already
suggested by the nests hanging from trees and woven
around the cross-bars of telegraph poles.
At thirty miles xrom Vera Cruz, near Soledad, the
foothills are reached and in this well-watered tract
the tropical vegetation is luxuriant in the extreme.
The ridges of lava that mark the base of Orizaba are
not at all like the Drakensberg, severely bare and
drearily rugged, but they are absolutely smothered
with rich verdure from foot to crest, and in the
canadas or rav'nes now visible, as the train emerges
from successive tunnels, there is a foliage of increas-
ing gorgeousness. Between Camaron and Cordoba
the botanical wealth of the tropics is lavishly dis-
played; nature, stimulated by warmth and moisture,
has clothed the earth with splendor. There are the
scarlet hibiscus, purple bougainvillea, the lavender
'.;'^.
TROPICAL VEGETATION
IS
plumbago, crimson oleander, pink azaleas, the yellow
and red flags of the coleus, even magnificent orchids,
with creepers of eveiy shade of green festoonmg the
forest . ...
Soon the train passes coffee plantations. The wild
undergrowth has been cleared, but the larger trees are
left in place, so as to give shade to the coffee shrubs
(five to six feet high), which are planted between
them. The young coffee shrub is delicate and must
be protected from the direct rays of the sun for at
least two years; maturity is attained in the fourth
year. The plants live 25 years and require compara-
tively little care— less than sugar, for instance.
Speaking of these matters, it may be noted that
chocolate is indigenous to Mexico and the word itself
comes direct from the Aztec chocolatl' ; nevertheless,
Mexico nowadays imports chocolate from Guatemala
and Caracas. Shade is imperative for the young
coffee plant ; in many cases it is cultivated under the
protection of banana pilms. This is the practice also
•The Aztec languaRe is still spoken by a million people, chiefly in
the S ates o Puebla, Jalisco, and a part of Vera Cruz; U .s a semr-
flictionaT language like 'the Maya in Yucatan. The Otomje " ab^'-J e X
different from the Aztec; it is monosyllabic and Pf"^^^ '/, °'f L-a' '
spoken by less than half a million people, chiefly m '^e States of Hidalgo.
Queretaro, and Mexico. Otomie in structure J,«embles Chmese and.
indeed, it has been claimed that the modern Chinese immigrant an
make himself understood among the Otomie Indians, but this, ao 1 was
told by Don Carlos de Landero, is neither vera nor ben trpvato It is
a mere philological analogy." However, the perpetuation o* these
ancient tongues is an interesting fact. Occasionally .t is a nuisance be-
cause of the difficulty of transmitting intelligence. At 11 O™- *°^ ""
ample, there are a number of men working underground th?.' do not under-
stand Spanish or its Mexican variation, and they have tv> be shown what
to do by signs.
l6
AMONG THE MINES OF MEXICO
fl
in Ecuador, Peru, and Brazil. It is said that the best
coffee in the world comes from the famous Youngar
valley, in Brazil, where it is grown in an old ceme-
tery under bananas. The yield is only a few quintals
per year, but this coffee fetches enormous prices. As
a rule the small berries (canicalilla) are preferred, but
the Youngar coffee is of large grain. Owing, how-
ever, to rankness of verdure, many of the Mexican
plantations looked so overgrown as, by reason also
of the trees retained for sheltering the coffee, to seem
like the bush primeval.
Soon we saw the yellow gleam of oranges and
limes amid dark foliage; picturesque hamlets ap-
peared, with red-tiled roofs and thatched houses, and
white-clad peasants. At the railway stations there was
always a crowd of fruit-sellers; bunciics of roses and
magnificent bouquets of gardenias were purchasable
for a song. But the panorama of life and color suf-
fered eclipse as the darkness of the tropical night
came suddenly, without any intervening twilight.
We lost the famous view of the f^arranca de Metlac,
but even in the dim starlight I made out the outlines
of the curved steel bridge, as the train swung round
it; there was the gleam of the torrent below, a feel-
ing of space and dark void, with the lights of dwell-
ings far away.
For the town of Orizaba most travelers have a
kindly feeling, because it brings the first sleep on
shore after the sea voyage, it means a good dinner at
the Trand Hotel de France and a perfect cup of coffee
TFIE MALTRATA VALLEY
»7
made from berries prown near the neighboring town
of Cordoba. Early breakfast in a patio (courtyard)
bowercd by bougainvillca, to the music of a fountain,
gave the bracing morning air a perfume and a fra-
grance long to be remembered. The mountain is vis-
ible from the town, but the view is not impressive. On
resuming the train journey, we were soon climbing
a heavy grade, circling the famous Maltrata valley
and ascending 4,(XXJ feet more in a distance of 30
miles. One looks down over precipitous slopes of
vivid green along narrow gorges that lead to a valley
cradled among the onlooking mountains and check-
ered \.- . squares of cultivation The little huts and
the clusters of trees look li\. playthings of a
doll's house, infinitely far away „ "d quite detached
from the busy life that throbs through the train with
every effort of the locomotive. This view of Maltrata
bears some resemblance to that obtained when de-
scending from the upper to the middle plateau of the
Drakensberg, Pietermaritzburg taking the place of
Maltrata.
/^
ij
J I
t
Chapter 4
11
THE PHYSIOGRAPHY OF MEXICO-OUTLINES OF
HISTORY — AT ESPERANZA — THE MAGUEY AND
PULQUE — A NATIONAL HABIT — ARRIVAL AT THE
CITY OF MEXICO.
S everybody ought to know, the
interior of Mexico is a high
plateau enclosed within moun-
tains of volcanic origin; this
plateau rises suddenly from the
lowlands that fringe the east-
ern coast; it is bounded west-
ward by the Sierra Madre
mountains, a part of the American cordillera,
on the farther slope of which there is a
sudden descent to the coastal plains of the
Pacific. In traveling from Vera Cruz to Mexico City,
a part of this structure is made manifest. The tierra
caliente, or warm lowlands, forms a narrow strip, to
which succeeds the temperate zone or tiena templada,
b'^twfien 3,000 and 6,000 feet above sea-level; then, by
abrupt ascent, one comes into the tierra fria or cold
country of the high tableland, at an altitude of 6,000
to 8,000 feet. Any rigor of climate such as might be
due to a high altitude is tempered by the latitude, so
that Mexico City, at 7,349 feet, and a little south of
^
■■
OUTLINES OF HISTORY
19
Lat. 20° North, has a temperature ranging between
60 and 75° F. the year round.
Mexico is 1,950 miles in greatest length, from
north-northwest to south-southeast; her northern
frontier is 1,500 miles long, while at the isthmus of
Tehuantepec the breadth of land has narrowed to a
neck of 130 miles, separating the two oceans.
A few dates will recall the history of the country.
Cortez and his company of adventurers captured the
City of Mexico in August, 1521. Three hundred
years of Spanish government, varied by revolutions,
ensued. In 1810 the people finally revolted against
Spanish domination and after an internecine strife of
eleven years, independence was gained. Iturbide, in
command of the insurgent troops, marched into
Mexico City on September 21, 1821. It was almost
exactly three centuries since Hernando Cortez made
his triumphal entry. In 1821 Mexico owned an enor-
mous territory; besides the lands of the present Repub-
lic, she ruled Guatemala, and to the north all that part
of the United States (up to Canada) which is west
of the Red and Arkansas rivers. Much of this domain
was lost as the result of the war with the United
States in 1846 and 1847. Peace was made by the
treaty of Guadalupe Hidalgo in 1848. In the territory
ceded at that time was the whole of the Rocky Moun-
tain region and California. I have never seen it re-
marked that while this treaty was signed on February
2, 1848, the first discovery of gold, by James W. Mar-
shall, at Coloma, was made on the January 19 pre-
ao
AMONG THE MINES OF MEXICO
ti
1^
ceding, or two weeks earlier. Mexico did not know
what she was losing and the United States did not
know what they were gaining. It is certain that had
the goldfields of California remained under Mexican
rule during the days of early discovery and prolific
production, there would have been complications,
into which the European governments might readily
have been drawn by reason of the magnitude of the
prize at stake. It was fortunate indeed that Califor-
nia became United States territory before her mineral
wealth had aroused the greed of the nations.
To return to our story ; we had seen Maltrata and
had reached Esperanza, 8,044 feet above sea-level.
Here the plateau extends with a sandy severity re-
minding one of parts of Arizona; from the moist air
of Hie tropics we had passed into the dusty winds of
me highlands. To the north, Orizaba hid his great
head under a panoply of cloud and over the brown
plains to the west were the white summits of Popo-
catepetl ('the smoking mountain') and Ixtaccihuatl
('the white woman'). Thib part of Mexico is largely
given to the cultivation of the maguey or aloe, the agave
Mexkana. Just beyond Apam the valley widens, be-
coming one immense plantation of maguey, reaching
in ordered sequence and in lines of mathematical reg-
larity to the dark hills in the south. The accompan
ing photograph illustrates the appearance of such
plantation. Maguey is the plant the fermented sap oi
which yields pulque, the national drink of the Mexican.
mmq.
i .
mma
THE MAKING OF PULQUE
ai
It is the 'century plar ' which got its name from the
i(^ea that it blooms once in a hundred years; which is
true enough in one sense, but the maguey does not
bloom each one hundred years or at the end of one
hundred years. It matures in seven years; at
that time the central shoot springs up with extraor-
dinary rapidity to a height of six or eight feet, and
blossoms. But when cultivated as the source of
pulque, this flowering of the plant is not permitted;
as soon as the stem gives evidence of emergence, it
is cut at the basal socket, so as to form a bowl in which
L.'llects the sap intended for the nourishment of the
gigantic stem we associate with the 'century plant.'
If the incision for the removal of the heart of the plant
is done too soon or too late, it dies unproductive. The
sap oozes into the socket and is removed twice a day
at first, and then each morning. It collects at the rate
of one to two gallons per day until, after about three
weeks of tapping, the plant is exhausted. In extract-
ing the sap, a slender gourd is used as a siphon; the
operator places one end in the bowl and the other in
his mouth, then he draws the sap into the gourd and
pours it into a sheepskin bottle. These bottles are
emptied into a pigskin bag, for loading onto the mules
and burros that carry the liquor to the hacienda or farm,
where it ferments over night, so as to be ready for
transport to the City early next morning. In the
course of travel this liquid intoxicant gains the smell
of the untanned raw pigskin, acquiring a filthy odor,
22
AMONG THE MINES OF MEXICO
'I I
{^
so that the pulquerias or saloons at which it is sold give
forth a noisome stench. It is the whisky of Mexico
and when fresh it is said to be nalatable. To me it
seemed to have a smell compounded of sour milk and
tainted meat ; it is good only (if at any time) when ab-
solutely fresh, that is, when drunk in the locality
where it is gathered. Mescal and tequila are other alco-
holic products of the maguey; they are derived from
the distillation of the roots. From the heavy pointed
leaves, five to eight feet long, the Aztec made the
paper on which his picture-writings were recorded.
The modern Mexican uses the fibres of the leaf, after
the plant has been exhausted as the source of pulque,
to make twine {pita) and rope. With it he also makes
the ayate or coarse cloth in which earth, corn, pro-
visions, almost everything, is packed for transport on
his own or his mule's back; for instance, the pigskin
bag holding the pulque is held in an ayate. It is said
that 1,300,000 pesos' are spent each month in Mexico
City for pulque, mescal, and tequila.
It is recognized by physicians and other thoughtful
men that the drinking of pulque is demoralizmg both
physically and mentally. (So also is whisky, es-
pecially bad whisky. An observant Mexican would
find abundant cause for commenting upon the demor-
alization of the American and Englishman that soak
themselves with poor whisky and make fortunes for
'Throughout these pages the Mexican currency will be expressed
in terms of pesos and ccntavos, while the gold standard will be expressed
in terms of 'dollars' and 'cents.' One dollar is roughly equal to two pesos.
wmmmm
bC'i.-toLf..
■Hi
.tX^^'jU.-.
TSfV
•.'■if I -/Zt
S^
f ft
If %
.1
i%
\^ \
THE ADMINISTRATION OF DIAZ
23
the distillers.) Efforts have been made to curb the
habit by moving the pulquerias farther from the centre
of the City. The chief obstacle to such regulation is
the long leases held by these drinking-places.
Barley and i.orn, probably wheat also, could be
grown on the land now devoted to the maguey. In
these cereals the country cannot supply the needs of
the population. The duty on wheat was reduced for
three months in 1905 by reason of the scarcity of flour
and the hacendados tried to put up prices by creating
a 'corner.' In such matters as these President Diaz
is enlightened; he abominates strikes and is opposed
to monopolies injurious to the community ; although
there is one glaring exception to his usual methods.
I refer, of course, to dynamite, in which commodity a
monopoly has been legalized. This is the weak spot
in his administration; r >me of his personal friends,
and even his son, are interested in the concession that
has been so hurtful to the mining interests.
We reached Mexico City after dark, but the bril-
liantly lighted streets and crowded thoroughfares
gave an impression of pleasurable life. That night I
heard a splendid band (of the police) in the patio oi
the Iturbide hotel, playing in honor of the convention
of American railway passenger agents. The volume
of inspiriting music awakened every corner of the
building, which was once Iturbide's palace. But if
the first Mexican emperor had revisited the glimpses
of the moon, he would have bent his head with shame.
^ ^ jy • £±witm'm'"i ix«.^i»/^T .iirs.?^' ■
'r^s^'-'msti'.-
i
24
AMONG THE MINES OF MEXICO
On the second floor, there is a corner room that once
held a shrine; it was Iturbide's chapel, and now it is
a trunk-room wherein are deposited the multitudi-
nous wares of itinerant Chicago drummers! Es triste.
It reminded me of Kingsley's words, inscribed upon
the drop-curtain of the Tabor Opera House at
Denver:
i;
"So fleet the works of man, back to the earth again ;
Ancient and holy things fade like a dream."
(ri)af ter 5
GEOLOGY ALONG THE RAILROAD — PRECIOUS
METALS IN THE VOLCANIC DUST — VEIN FORMA-
TION—THE SULPHUR OF POPOCATEPETL.
HERE was not much geology to
be deciphered along the railroad
from Vera Cruz to Mexico City,
except the wonderful construct-
ive features to which the Sierra
Madre Oriental and the great
Mexican table-land owe their
origin. The plains of the coast
are made of Tertiary sedimentaries, from the actual
dunes of the shore to the foothills of the Sierra Madre,
where the railroad enters the Middle Cretaceous, the
rocks of which are largely covered by the lava emitted
from young volcanoes. At Penuela there is a quarry of
Middle Cretaceous limestone, which is the stone em-
ployed in building the mole and breakwater at Vera
Cruz. Coming west, between Maltrata and Boca del
Monte, the railroad cuttings expose intensely folded
strata, traversed by faults that divide the Cretaceous
series in step-like succession. Above Boca del Monte,
the sedim^- t ries are crowned by remnants of lava
streams and volcanic dust, in part consolidated as tuff
and in part loose earth, but hardly warranting the idea
a6
AMONG THE MINES OF Mi XICO
once prevalent that these deposits Iiid been accumu-
lated by wind or, in geological phrase, were of eolian
oripii'.
""'hrough this volcanic material, ummocks of the
' re.; ceous make an appearanc as at San Andreas.
I'll- :■ st of the journey to Mexuo City is lade over
i'laUH broken by occasional rocky domes and car-
petet: with volcanic scoria, tuf? nd -nalpais.' Such a
IT ('in of olcanic dust is oitin termed 'ash.' A?*-
is the product of combustion; ti is mat. ria! is the re-
sult I ! v:)lent explosion and fragmentary ejection
from tlic > cnt of a volcano; it is lava that has been
torn into bits hy the expansive force of steam, formed
by release pressure. It is, therefore, 'dust,' that is,
minutely subdivided rock This material, call it what
you may, is of interest to the miner, because (Ccasion-
ally, when mixed with the products o the df..ay - '"
other more ancient rocks, it carries gold. Near Jalapa
a large area is aid to give assays of one to four grams
of gold per metr ■ ton^f 2,204 pounds. Two erams is
claimed to be ar; aver- ;e, and .is this material cya
nides readily, it may become commercially valuable.
An analogous occurrence is found in the ma; ve vol-
canic rocks i the ranges northwest ' Mex
where both the precious metals exist ing - _ -i
fissuring, to the extent of one or tw< ;ram gi'old
and nine grams of silver per ton. T: e met.. is tiavc
'This is the word th.it in its corrupted for- malarai, is used
.Arizona and ihc Southwest Kencrally. tci <lesigii.it.- he biack lava-hcid^
It cjmcs from t!ie Spanish ntiil, bad, aii'l fais, countrj
b l« w
A Country House in Mexico
? l;
kt
SOLFATARIC VENTS
27
been detected in places where solfataric action is in
evidence, especially along cracks in the solid hyper-
sthene and hornblende-andesites. The richest ma-
terial is found in a concretionary form, together with
hyaline silica, resembling the glassy quartz of ordi-
nary gold veins. The waters doing this work are
cold. It is probable that the gold and silver are de-
rived from the decomposition of the iron pyrite, which
abounds, finely disseminated, in minute crystals,
throughout the rocks of these localities. Small crys-
tals of hematite have also been distinguished, more
usually in the rotten rock. It can also be said that
the greater the decomposition, the greater the con-
centration of gold and silver in the cracks traversing
thif formation. In the dry climate of the Mexican
plateau, meteoric water dissolves the carbonic acid,
which, sinking below the surface, exerts a solvent ac-
tion. In the Guadalupe range, five miles north of the
City, there are narrow solfataric vents, the warm
waters of which have deposited silica in the form of
quartz together with gold and silver, the first in traces
and the second to the extent of eight grams per ton.
These occurrences, while of no immediate commer-
cial importance, are interesting as affording present-
day manifestations of the manner in which thermal
waters make ore. The same process continuing for
a long period, and protected from erosion, would lead
to the creation of a valuable ore deposit.
Much has been said of the sulphur in the crater of
Popocatepetl and a company formed to exploit these
.m^;^f«ifei'
i
t'
3&
AMONG THE MINES OF MEXICO
deposits of brimstone has obtained some notoriety.
Not long ago Senors Jose G. Aguilera and Ezequiel
Ordonez descended into the crater and found a de-
posit of sulphur not more than 15 centimetres thick
and so distributed as to be of no industrial value.
Although exceptionally pure, the sulphur was in the
form of small particles mixed with volcanic dust
around cold fumaroles; these emitted steam with
traces of sulphuric acid, the decomposition of which
led to the precipitation of the sulphur. IL was the
result of deposition for a period of twenty or thirty
years. There is a story — and it is Prescott who tells
it — of an ascent of Popocatepetl, made by some of
the men under Cortez, to secure sulphur; but these
explorers did not go to the bottom of the crater,
which is 800 feet below the summit; they went only
as far as a fumarole on the lip of the crater. After
all, the quantity of sulphur that they needed — and
they took — to make gunpowder, was insignificant.
•I
1^
-1
<ri)af Ur 6
THE CITY OF MEXICO— FIRST IMPRESSIONS— THiZ
SCHOOL OF MINES— MEMORIES OF DEL RIO— THE
METEORITES — CORTEZ.
EXICO is the Paris of the
American continent. The air is
clear and balmy with the feel of
the tropics, the early mornings
prompt a canter on horseback in
the park at Chapultepec, the
story of the City gives it the dig-
nity of history and the glow of
romance, the actualities of today are touched with the
silken hand of luxury; life is rich, gay, and progres-
sive. The brutality of mere materialism and the
squalid splendor of newly made wealth are not evi-
dent, the invasion of Anglo-American energy and
capital has prompted many sanitary reforms and
municipal improvements, but the practical man from
the North is insignificant in numbers, so that while
he may be partly responsible for the cleanliness of the
streets, he is unable to spoil the distinction of a com-
munity, the members of which go to Paris as to the
Lourdes of a fashion saint, to bring home a taste in
clothes and horses that enhances the attractiveness
of the daily promenade, giving grace to the Spaniard
and adornment to the Mexican. Time was when the
Ji
30
AMONG THE MINES OF MEXICO
City of Mexico was far from salubrious, when her
streets were badly paved and her hotels among the
worst of their kind; but all that has been changed.
Of comfortable hostelries there are plenty; the restau-
rants afford a great variety of good cuisine, and the
clubs— the Jockey, the British, the American, and
several others — give sojournr^rs the hospitality
worthy of a metropolis.
There are many fine buildings in the City. The
cathedral and the museum are well known to travel-
ers; the building in which the School of Mining is
now situated is more than a century old, and it is full
of interesting traditions. One of the founders was
Andres Manuel Del Rio, the great Spanish mineralo-
gist, who adopted Mexican nationality; he belonged
to the Freiberg school, and during Humboldt's time
was sent by the Spanish government to Mexico with
a view to stimulating mining education. He founded
the collection now to be seen in the School of Engi-
neering, which includes that of Mining. There is a
story told of Del Rio and Humboldt that is not with-
out humor. Del Rio found a new mineral, which he
called plomo rojo de Zimapam or red lead; it was a
vanadate of lead, vanadinite. Humboldt visited
Mexico at that time— between 1804 and 1808; Del
Rto gave him a specimen and his notes concerning
the discovery of the new mineral. Humboldt took
them to Europe with him; subsequently, he wrote to
say that he had lost these notes and the specimen
Itself in some boxes that fell overboard at sea. But,
METEORITES
31
strange to say, a few years later the vanadium min-
eral was discovered in Scandinavia. In 1836 Del Rio
made a sarc-.stic reference to the episode in a pa->
that he wrote as a sort of protest against the injus. .
done to him, in calling the new metal after the Sc. n~
dmavian goddess instead of— for example— Riita. For
his was the discovery.
In the museum there are some fine meteorites-
one specimen weighs 14 tons; it came from Chihua-
hua Another, called the San Gregorio mass, has in-
scribed upon it the following Spanish rhyme:
Solo Dies Con zu-Poder
Este fierro destxuira
Per ce en cl Mundo no Abra
Quien lo pueda Dsfaccr.
I trust no scholar, critical of the Spanish of this
quotation, will impute its apparent errors to me I
give the words exactly as I copied them from the
mscnption Which may be interpreted: "Only God
with his power can destroy this iron, for there is no
one in the world who is able to unmake it." It was
discovered in the year 1600 and weighs 10,000 kilo-
fn^'n Jn'^'i'^' '"^'''^^ '' ^^""^ ^^^ San Gregorio,
>n the De Allende district of Chihuahua.
fh.r ^Y observatory on top of the building
there ,s a splendid view of the city and its environs
Z'T^'^'^'f' ^^"' '^' ^^^^"-^ °f the cathedral
and he domes of the churches of the Profeso and
Santa Teresa nse finely above the multitudinous
II
32
AMONG THE MINES OF MEXICO
buildings, cut into squares by straight streets, beyond
which are the dark foothills dominated in the dis-
tance by the broken crest of Ixtaccihuatl and the big
cone of Popocatepetl. To the southeast, one can see
Iztapalapan — now Istapalapa — where, on the eighth
of November, in 1519, Hernando Cortez met Monte-
zuma, and the pioneer of European invasion ex-
changed courtesies with the poor king whom he so
utterly destroyed within less than a year.
At that time Iztapalapan was a place of twelve
thousand houses and it was under the rule of Cuitla-
hua, the brother of Montezuma. Through the town
passed one of the three great causeways that led
across the lake to the City of Mexico itself, and it
was over this causeway that the Spanish adventurers
made their way. Today Istapalapa is a small village
and where once spread the waters of the lake, there
is marshy ground. The causeway is obliterated by
a modern street, that of Acequia, which took advan-
tage of the secure footing thus afforded. It starts
from the portals of the Plaza de la Constitucion, as
does also, in the opposite direction, northward, the
San Andreas street, which merges with the road to
Atzeapotzalco; this was the line of the causeway to
Tlacopan or Tacuba along which the Spaniards re-
treated on the occp.-ion of the Noche Uriste, that black
night of July 1, 1520, which saw them all but anni-
hilated by the fury of the Aztec pop" 'ace. At Po-
potla the survivors halted under a ; that exists
ii^M
•jvi'^s'^y
THE BATTLE OF OTUMBA
33
to this day. It is now guarded by an iron railing,
but despite even this protection it is endangered, for
I read in the daily paper, during my visit, of the
arrest of a vandal, who wanted a piece of the bark to
add to his collection of curios. If ever there was a
time in the Spanish conquest when Cortez and his
fellow pirates were heroes indeed, it was just after
their sad halt at Popotla. Of the number that had
entered the City only a third (250) of the Spaniards
survived and of their native auxiliaries only one fifth
(1,000). They had lost most of their horses, all their
bMtillery, all their muskets, so that there remained
only their swords and their courage. But Cortez
faced the music like a man and was confident even in
the hour of deepest gloom. Scarcely one week later,
on the plain of Otumba, this handful of men met a
multitude of natives, estimated all the way up to
200,000, and beat them off the field, mainly by reason
of the desperate resolve of a few of the cavaliers, who
followed the immediate lead of Cortez and penetrated
the thick of the combat in order to kill the chieftains
on the opposite side. It may have been comparable
to the attack of a centre-rush of a senior football
team mto the midst of a kindergarten, but it was
rend^^red magnificent by reason of the astonishing
disparuy of numbers and it proved abundantly that
the superiority of race was not due to physical
strength alone.
It is a fact, both significant and pathetic, that
K>.':-^.
/I
!
34
AMONG THE MINES OF MEXICO
while there are today several statues to the last
Aztec king— Guatemotzin or Cuitlahuac— more par-
ticularly the fine monument in the Paseo de Reforma,
and while nearly every city in Mexico has a bust of
Hidalgo, the priest who started the final revolution
against Spanish rule, there is no statue to Cortez in
the whole length and breadth of Mexico.
I
!
I
^
^9magF-"]g^m^,
The TiMiim Ca.mh or thk Hi. Dkm Mining & Railway Co
(TlKiptftr 7
EL ORO-RICH MINES -THE GEOI OGY OR tuv:
ROM Mexico City I went to El
Oro. This mining district is 90
miles northwest, and while most
of it is within the State of
Mexico, its northern portion ex-
tends into the adjoining State
of Michoacan. At the time of
my visit (October, 1905) El Oro
was attractmg much attention; a new orebody in the
Esperanza had s. - .p the shares (of the company
owning that min • ••, , ondon; El Oro Mining 1^
Ra^^ay Company ...r.. b.d risen in sympathy:!) *
Es^rdlas was makm., . boor . market in Mexico Cu
and Vu:tona y Ane . ,v.. fluctuating in a n»^an.-;
beloved of speculators. As a foundation u. .'
,o" •"? .''''^'^'■^^' ^ ^^""d 'odes of unusua. ^eo-"
ef n ed" h^' '"'/ metallurgical practice thatfe^
resented the sum of great technical ability.
1 le mmes are situated on the slopes of a ride-e
un tTT '"^ ^'^^^^ *^^ -"^^' through wS
way On th""" '"^ ^' '""^ ^'^^'''^" N^*--' Rail-
way. On the near (eastern) side are the Mexico,
%' ''^ iTi
H I
36 AMONG THE MINES OF MEXICO
Esperanza and El Oro mines; on the farther slope
is the Dos Estrellas. The three mines first men-
tioned follow a series of veins of which the San
Rafael is chief; these dip into the mountam. The
Dos Estrellas, on the other side, also dips to the west.
The bush-covered summits of the ridge consist of an
andesiie lava, while the mine workings are mainly m
shale. A covering several hundred feet thick of
(probably Pliocene) andesite is spread over the an-
cient eroded surface of a (probably late Cretaceous)
shale, in which occurs a series of quartz lodes, con-
taining gold and silver. The cap-rock forms part of
an extensive extrusion of volcanic material, the main
vent of which is not known; although in the mines
there have been encountered tongues and irregular
bodies of the same rock, suggesting many minor
places of emission. The shale is thinly laminated,
black, and calcareous; it contains occasional layers of
limestone. According to Robert T. Hill, it is the
formation in which occur many of the best mining
districts of Mexico. The relation of the cap-rock,
the shale, and the quartz lodes is seen best in the
Mexico mine, which, being a young property, is easily
accessible throughout. The accompanying cross-
section (Fig. 1) through the main shaft is based upon
a tracing given to me by Mr. Fergus L. Allan, super-
intendent of the mine.
The shaft goes through the andesite of the cap-
rock for nearly 600 feet and then penetrates the shale.
After passing through this shale for 450 feet, the
^i
41 iiiia I
SrvTi > rn TiiK l.vsT tiF tmi A/tkc Kim
GEOLOGIC FORMATIONS
37
E3 0l.!)t« ANOf'jlTE
Fto. 1.
Cioss-Section Tbioucu Mai» Shaft of xue Mcxic» Mirrt
(I
]!
u
^ \MONG THE MINES OF MEXICO
•' ters andesite and continues in that rock
to . item, just below the sixth level. This v -
desite, in the foot-wall country, is the same rock as
the cap; it is evidently younger than the vein and,
therefore, later than the other andesite, w' ich over-
hangs the San Rafael vein, as seen in the first four
levels west of the shaft. Some distance west of the
San Rafael vein, in the Nolan mine, narrow intrusions
of this younger andesite have been found running at
right angles to the course of the vein. The deeper
levels have not found the older andesite on the hang-
ing wall; it antedates the vein, for mineralization
extends into it. The same tongue of andesite occurs
in the northern workings of the Esperanz;-. and m a
similar position relative to the vein. In some places
ore has been found in this andesite, where it is ad-
jacent to an orebody in the vein.
The lode consists of banded quartz, built mainly
of rock in place, which has been shattered and
silicified, the whole body attaining a width of 30 to
50 feet. The ore occurs in streaks parallel to the
walls of the vein, in some places combiniiifr and oc-
cupying the larger part of the space between. This
quartz contains just enough iron oxide to color it;
when banded it is always good, the poor portions of
the vein being characterize 1 by massive white quartz.
The shale adjoining the loJe is bent and shattered;
it shows numerous streaks and small veins lying
parallel to, and running into, the main vein. That
portion of the vein which is found at the old surface
.L -i
^w
THE VEIN IN THE MEXICO MINE
39
Fic. 2 Cuoss-StcrioN or Veim w thi Mexico
J
! S
40 AMONG THE MINES OF MEXICO
of the shale has a width of 30 to 40 feet ; it had evi-
dently undergone erosion before being covered by
the later flow of andesite. As a rule, where the apex
has been thus exposed to weathering, the San Rafael
vein is richer than usual; it has undergone a note-
worthy concentration. In the southern portion of
the Mexico mine the apex of the vein is found at the
surface of the shale, but farther north the vein comes
to an end 100 to 250 feet below the old surface of the
shale. When the vein does not reach the old sur-
face, it frays out into stringers, bent over at their
ends, as shown in Fig. 2. The particular vein shown
in this sketch carries an average assay-value (11 dwt.
gold and 6 oz. silver) right from the start; it widens
until, at the fourth level, there is 20 feet of quartz;
on the second level, only 25 feet above its blind apex,
there is no indication whatever of the proximity of a
lode.
The conditions just described as occurring in the
Mexico mine are found in the Esperanza and F.l Oro
workings, which extend in sequence southward.
As seen in the El Oro mi.ie, the veins leally con-
stitute one big lode-channel with portions of country
between, that is, the distinction between what is ore
and what is worthless quartz is purely commercial,
based on assays, and not upon geological and struc-
tural distinctions. At first the Branch vein, one
member of the system, was found to be rich enough
to exploit; then a smaller sireak on the hanging wall
of the big Main vein (the San Rafael) was vvorked.
THE EL ORO VEINS
4»
and finally the foot-wall portion of the San Rafael
was stoped, to be followed by the exploitation of
various subordinate nr ibers of the series, as they
were determined to be rich enough in gold and silver
to more than defray the costs of mining and milling.
A typical cross-section of the lode-channel shows
sundry branch veins, then the foot-wall orebody of 35
feet, then streaks up to three feet wide between the
foot-wall ore and that of the hanging, which is 40
feet wide; finally, beyond these there is the Branch
vein, 5 to 18 feet wide.
At the north end of the mine the orebodies of the
foot and hanging are separate; they come together
in a distance of 700 feet and form one width of 80
feet, which is maintained nearly to the south end of
the shoot,, in the vicinity of the incline shaft. The
ore on the hanging is fairly uniform in value across
n?. f'.i'! widtS, but the foot-wall ore is best on the
li.m^iiig si !-, even after they unite the individuality
of ' streaks is maintained. When the bands of
ricli re in this mine terminate, they do so first by
narrowing, and then by the splitting or fanning out
ol the mass of quartz that contains them. Divergent
streaks connect the various orebodies, and some of
them are rich enough to be stoped. The whole lode-
channel is interrupted at intervals by a succession of
faults dipping at 65 to 70°, except the southernmost
or diagonal break, which is 35" ; all of them dip north.
Water was first struck in the El Oro mine at 425
to 430 feet below the cap — for all measurements are
1;
4>
AMONG THE MINES OF MEXICO
li
made from this old surface. Maximum water was
encountered at 1,200 feet. The Somera shaft began
to show a heavy inflow between 786 and 1,000 feet,
especially from 900 feet down; the water entered
along stringers on the hanging-wall side of the lode.
At 1,000 feet, the cross-cut (90 feet long) to the lode
cut more water along other veins, so that when the
lode was finally struck there was no great addition
to the inflow. The water in the workings on the
main lode remained ai the 786-foot level until the
lode itself was cut at 1,000 feet. The faults appear
to be impervious and serve as barriers; each block has
tu be drained separately. At the end of the rainy
season, surface-water makes itself felt in the mine,
but only in the northern workings, where it seeps
down through cracks in the cap-rock caused by
mining operations, more particularly the large stopes
on the San Rafael lode made by the Esperanza and El
Oro companies near their common boundary. The
rainfall apparently does not affect the inflow of water
in the deep workings, the mine-water (except in the
case above noted) having no direct connection with
the surface.
(ri)af>Ur $
GEOLOGY OF THE ESPERANZA MINE — INTEREST-
ING STRUCTURE — A BIG FAULT — RICH OREBODY
— STORY OF THE DISCOVERY — CHARACTER OF
THE ORE.
N the Mexico and EI Oro mines
there is some geology, which is
not particularly complicated, but
the ground between, ocupied
by the Esperanza mine, presents
many intricate problems.
There is a good deal of
geology in the Esperanza, and
there is a good deal of rich ore. The geological fea-
tures have been carefully studied by Mr. J. E. Sjmrr,
and the data embodied in my notes are largely the
result of his work, in association with the manage-
ment. The accoinpanying diagrams (Fig. 3, 4, and
5), and the geological plan of the second level, as given
in Fig. 6, are based on sketches and a blue print given
to me by Mr. W. E. Hindry, the manager. To him
and to Mr. W. H. Haynes, the assistant manager, I
am much indebted.
The main geological events, the results of which
are evident in the mine workings, are :
1. The deposition of the shale.
({
! M
44 AMONG THE MINES OF MEXICO
2. Intrusion of andesite in the form < dikes and
sills.
3. Faulting, involving several dislocations, one
of which became the channel of the San Rafael lode;
and later movements that displaced the lode.
4. Deposition of ore by waters circulating along
the channels made by the previous fracturing.
5. Intrusion of a later andesite that overflowed
at surface and penetrated the shale formation.
6. Cross-faults.
In Fig. 3 the San Rafael lode is shown as seen in
cross-section, looking northwest, in the northern por-
tion of the mine. The sequence of geological events
is indicated by the numbers 1 to 5. First, the shale
was ruptured and dislocated at least 1,000 feet— from
1 to 2. Then it was eroded and on it was spread the
andesite, the original surface of which (at 4) was
reduced by erosion to the present surface (at 5).
The thickness of this andesite cap ranges now from
nothing up to 700 feet. In the meanwhile the intru-
sions oi earlier andesite were also faulted with the
shale, as is suggested by a tongue of that rock indi-
cated on the diagram. In Fig. 4 the same sequence
is exhibited as is seen in a cross-section of the
southern end of the mine. In this case a higher
intrusion of earlier andesite is shown and also a
tongue of later andesite.
The lode, therefore, follows a big fault; but it is
itself faulted, as shown in Fig. 5, which is a longi-
tudinal projection N 60° E, magnetic. On the first
SimriNi; ( )hk
1
I
K \ /
^
-
i
• *
O.N riiK ( »
IT-'KIKTS UK (ir \N.Ml'ATO
MICROCOPY RESOLUTION TEST CHART
ANSI and ISO TEST CHART No 2i
1.0
I.I
IIM
132
iT 1^'
1.25 iu
2.5
2.2
2.0
1.8
1.6
^ APPLIED IIVMGE Inc
C^b'! ^Si - 0500 - Pfi.-
I
(
I :
»1
' -i
H ;
ii
r I
A BIG FAULT
45
»4'».w«> **4«t Mv»r4t^
Fig. 3. Diac:rau Showing the Sesies of Geological Events That
Brought Abouv the Present Structure. Cross-Section
of nosthekn portion of esperanza mine.
1 ^
{J ;(<
II
46
AMONG THE MINES OF MEXICO
level at a point 525 feet north of the El Oro boundary,
this fault cuts through the country and displaces it,
as measured by broken ends of intruded older an-
desite, 500 feet vertically. This same fault is evident
at the surface of the shale (now buried under later
andesite), for there is a drop of 160 feet in the bottom
of the cap-rock. This would appear to indicate that
the moven^ent transverse to the lode continued after
tHe later andesite overflow, so that in the main fault,
the total dislocation is measured in two parts, two-
thirds or about 340 feet of which occurred before the
cap-rock was formed, and one-third, or 160 feet, after
that event.
In the mine the lateral displacement of the San
Rafael lode is 130 feet, to the right. At the south
shaft the cap is 284 feet thick; near the north shaft it
is 165 feet higher (by reason of the rise in the ground
in a length of 1,600 feet, which is the distance be-
tween the shafts) plus the fault (160 feet), plus the
elevation, making the present thickness 165 -f 160 4-
284, or 609 feet. South of the fault the lode is en-
tirely in shale all the way down to the fifth
level; just below that horizon there is andesite on the
foot-wall and shale on the hanging. North of the
fault, the first level penetrates cap-rock, while the
second has shale on the foot and the older andesite
on the hangii.g. The third and fourth levels repeat
the conditions observed on the second. At the fifth
(still north of the fault) there is a change; at about
100 feet in the foot-wall the newer andesite (which is
Putting Timbers in Place
COMPLEX GEOLOGY
47
the cap-rock) appears at a point 500 feet north of the
fault and thence to the boundary of the Mexico mine.
At the sixth level the older andesite is seen in the foot-
wall south of the fault and looks like the top of an
Fig. 4.
Lode-Fault, San Rafael Vein. Cross-Section of Southern
Portion of Esperanza Mine.
intrusion; north of the fault, shale appears on both
foot and hanging, that is to say, we have the condi-
tions which exist south of the fault 500 feet overhead
— this being the measure of the dislocation. On the
i
n
48 AMONG THE MINES OF MEXICO
seventh level the older andesite appears along thj
foot-wall up to the fault, shale showing in the hang-
ing. North of the fault the lode is in shale as regards
both walls, with the newer andesite in the foot-wall
country (150 feet east of the lode) near the Mexico
boundary. At this same level — th seventh — the
newer andesite (or cap porphyry) '' s in the form
of an east-west dike, 153 feet thick > a point 825 feet
west of the lode, but its real shape has not been
ascertained.
All this refers to the San Rafael, the main lode
of the Mexico, Esperanza, and El Oro mines. The
interesting problem, at the time of my visit, was
whether the new West vein is faulted (see Fig. 6)
in a manner similar to the San Rafael or whether this
bonanza vein is younger than the fault itself. If the
latter be the case, the vein would go into the andesite
north of the fault at the third, fourth, and fifth levels.
The ore of the San Rafael extended up to the fault, the
break being clean. At the fifth level pay-ore was
broken almost up to the fault-line. The San Rafael
is generally more broken on the north side, the ore
not reaching up to the fault as clearly as it does on
the south side. If the West vein be later than the
fault, it is likely to be weak where crossing the latter
and probably it will be less rich in the andesite than
in the shale, the bonanza portions of the veins of this
district being in shale country. With the limited
data at my disposal, it seems to me unlikely that the
new vein is younger than the fault, because there is
Ai.
A RICH OREBODY
49
no evidence of its existence in the northern workings.
The new Esperanza orebody is a sight to gladden
the eyes of a miner. It is 680 feet long, with an
average width of 9 feet and an average yield of 75
grams of gold (or $49.70) per ton and 1,150 grams of
silver ($19.55) per ton. The shape of it is roughly
lenticular; it is widest about the centre and comes
nearly to a point both north and south ; in depth it is
1 T.T EsPEBANZA Fauli. After J. E. Spurr.
shaped like the bottom of a boat, with protruding
keel. Where first cut on the fifth level, there were
two veins close together; the first assayed $1.50 to
$2 per ton, while the other, or No. 2, to the west, \'ent
$75 per ton. Subsequent stoping gave a different
story; the No. 2 has been payable only for 50 feet
above this level, while the No. 1 gets into rich ore
so
AMONG THE MINES OF MEXICO
f ; f'
i n
three feet above and only 15 feet south of the cross-
cut.
At about 45 feet south of the cross-cut, the two
veins come together and make a width of 35 feet of
ore worth over $100 per ton. The moral is: If you
find absolutely nothing by drilling, do not cross-cut ;
if you find any encouragement whatever, cross-cut.
In the workings that I visited there were slopes four
feet wide of ore worth $500 per ton ; where the quartz
was rich, even the adjoining shale (penetrated by
small stringers of quartz) wis good enough to stope,
for it assayed 15 to 40 grams c'' gold.* Small bands
of shale included by the vein assayed equally with the
quartz. It seemed to me that, as compared with the
San Rafael lode, this bonanza vein was particularly
well defined; there was no gouge and the ehale at the
walls was broken off clean, without shattering or
twisting, the bedding of the outer country ly .ig flatly
right up to the ore. The vein is apparently younger
than the San Rafael, because there are few signs of
later movement, such as slips or gouge-seams. The
ore itself is beautifully ribboned ; minute crystals of
pyrite incrust the quartz, especially in geodes or
vups; the richest ore is mosceado^ that is, speckled
with argentite.
On the seventh level there is an interesting vein
occurrence ; this is a seam of pyrite called the 'sulphide
'A gram of gold is worth 66.4 cents and a gram of silver 17c. My
description of the 'rebody is based, it mast be remembered, on notes
made at the end r October, 1905.
'From mos a fly.
m^'^-ikii^
GEOLOGY OF THE ESPERANZA MINE
51
"1?
&'
W . S
bos;"
bji I*
S .SOB
o ..» g
S M O
"Spa
.9
I HI:
J^g-s s.s
Sa
AMONG THE MINES OF MEXICO
t ^
streak,' 26 inches wide, in the foot of the San Rafael
lode, which here is 22 feet wide. The sulphide streak
crosses the San Rafael and is therefore younger. The
foot-wall country in this part of the mine is porphyry
(andesite) and the sulphide streak is built up of
brecciated porphyry, the hanging being irregular and
penetrated by quartz veinlets, while the foot-wall car-
ries a gouge, beneath vhich the fragmentary char-
acter of the vein-stuff is evident. This vein carries
a pyrite which is coarser than that of the new West
vein and in the ratio of !2 per cent; the West vein
yields one ton of concentrate to 16 tons of crude ore,
that is, over six per cent.
In speaking of ore at El Oro as being worth so
many dollars, it is meant that it contains so many
pennyweights of gold, for the silver is not included.
This is largely a habit inherited from the days when
the silver was not extracted in commercial quantity.
A $7 to $9 (or 7 to 9 dwt.) gold ore will carry $1.50 to
$2 (or 2.5 to 3.3 dwt.) silver per ton. The gold is
free and in firi particles, rarely visible, while the
silver occurs chiefly as the sulphide (argentite), with
some chloride in the upper levels. The quartz is
extremely hard and flinty, beautifully ribboned in
lines parallel to the walls of the lode. In this respect
and in its general appearance it often reminded me
of the ore produced by the Amethyst and Last Chance
mines at Crecde, Coloiado, in 1894. Argentite occurs
along the lines of ribboning in minute streaks be-
tween seams of opalescent quartz; the natives call
•
3
H
■
K^^H
^^^H ^^H-'x
lp-
^^H^^Bi
r^Mn fl
Hi-'^^ .'•
^^^H
Bv^^^fl ^^^H
B'iw-i^ i
H^^H
I^Hf^^l
^^^^^^^^■^^H
^HttH J^^^l
E jbE^T i' ' ''^
^^^H
^^^I^H ' ' ' v^^jD
ISj """
l^^l
nl^
nl
^^^^^^^^H
K^^^BE/^H
^^l^^^^^n
^Bl^^ fl
HB^M>';''^
^Hl^^^^Hf
^^QVi> ;J
^^■iffiBfe^ll),.
^^^^EA^^BT^ v^~
9HH
HP.'Trfl
^^^^^H
I^B^''^'' il
^^^K^^
^^DB
Sill «
H|ft;d
^
n
H
.\l
GOLD PRODUCTION
53
.1
■1
these hilos, or threads. The ore is largely a replace-
ment, by silicification, of the encasing country and
this holds true no less of the andesite than the shale.
The Esperanza is sending mineralized porphyry to
the mill and mineralized shale to he smelter. Beau-
tiful pseudomorphs of quartz after calcite are fre-
quent, they appear as sharp scalenohedra and re-
semble the 'water quartz' of Cripple Creek. The best
specimens occur in the small 'horses' (or included
fragments of country) within the vein and on the
outside of the big pay-streaks. All the surrounding
shale shows the "^flfects of mineralizing activity and
the outside andesite will often yield traces of metal;
for instance, the old decomposed andesite on the fifth
level of the Esperanza assayed 0.29 oz. silver and
traces of gold.
At the time of my visit, at the end of October,
1905, the rate of production of the El Oro district was
slightly over $1,000,000 per month, distributed thus:
Esperanza, $650,000; Dos Estrellas, $240,000, and El
Ore, $200,000. An output of $12,000,000, 82 per cent
of it being gold, made El Oro the second most pro-
ductive gold-mining centre on the American con-
tinent.
i
i^,f I
ip. u
n
'I •
(Lfyupt^T 9
DEVELOPMENT OF THE MILLING PRACTICE AT
EL ORO — BEGINNING OF CYANIDATION — FIRST
BIG MILL — CHANGE OF METHOD — TUBE-MILLS
AND RE-GRINDING.
EVELOPMENTS in the mill-
ing practice at El Oro are full of
I interest. In 1873 a hacienda de
' beneficio, or reduction plant, was
I erected to crush ore and treat
the accumulated tailing from a
still older arrastre* and to this
_ - - _ -_ _ P^ant further addition was made
in 1885. The mill then included 25 stamps with
amalgamating tables. In 1890 the accumulation of
tailing made by the stamps was sold to a man from
Eutte, named Albertson. The tailing he handled
was richer than the ore being mined today. Never-
theless, the contract for the treatment of it was
cancelled after the purchaser had installed four
amalgamating pans, with settlers, and had started to
ship bullion. This was under the regime of General
Frisbie. In 1894 a Chilean mill was brought from
Chicago, to grind the ore after it had passed through
a Comet crusher. The Chilean mill did finer grind-
*The Anglicized form is 'arastra,' but there is no need to use it,
the Spanish term itself being preferable.
mMRmnm
Pi
AN EARLY CYANIDE PLANT
55
ing than the stamps, which at that time were also
preceded by crushers, of the Blake type. The mill in
tuin left a dump that, eventually, as methods im-
proved, it became profitable to e-treat. Late in
1894, James B. Ha^'gin bought control. In the fol-
lowing year the old mule-stable was converted into a
cyanide annex. Redwood tanks 24 feet in diameter,
with 4>2-foot staves, were erected ; the sump-vats were
larger, with 6-foot staves. The tailing was carried, in
boxes on the backs of peones and in hand-barrows, to
the vats. Cyanide solution was first introduced by
upward percolation through a false bottom, the suc-
ceeding water-washes being applied from above.
This was followed by precipitation on zinc shaving,
with acid treatment for the zinc 'shorts,' the bulk of
the precipitate being carefully washed and melted
forthwith. The bullion thus obtained was of extra-
ordinary fineness — 960 to 980 — without the use of
any nitre in the melting. This was one of the first
successful cyanide plants in Mexico. With only the
addition of the small cyanide annex just described,
the mine paid $1,000,000 in dividends up to May,
1898, besides meeting the cost of various installations,
including part of the 100-stamp mill taken over by
the English company, which now controls the prop-
erty.
The first 100-stamp mill was designed under the
Haggin-Frisbie regime and was only expected to
crush 4,500 tons per month through a 60-mesh screen.
When the property was purchased by the Explora-
f ■^■H
56
AMONG THE MINES OF MEXICO
4^
u
tion Company in 1898, this mill was too near comple-
tion to be altered. The slime-plant was added in
1900, after the present company had been formed.
W. K. Betty had conducted a series of experiments
for the new owners and double treatment was then
adopted for the slime-plant. This was only making
the best of conditions as they were found ; hence the
pile of stored tailing now about to be re-treated.
The general plan of treatment was as follows:
From the stamp-battery the pulp passed over copper
plates and was then divided, by spitzkasten, into
'coarse sand,' 'fine sand,' and 'slime,' each product
receiving individual treatment. The sand underwent
double treatment in South African style ; it was first
cyanided in collecting-vats and then dropped into
cars that removed it to the treatment-vats. The
slime was caught in a settling-vat and thence went to
the treatment-house, where it was agitated by jets of
compressed air. After treatment, the sand was
dropped into cars underneath the vat, while the slime
was flushed out with water in the ordinary manner.
In the meanwhile the capacity of the mine grew,
not only by reason of the discovery of new orebodies,
but indirectly through the cheapening of operations,
so that further enlargement of the mill became
prudent. In 190.S another, and the last, addition to
the reduction plant was made. The aew mill of 100
stamps, with its up-to-date cyanide equipment, differs
from the old one in five respects, namely:
.A
CYANIDE TREATMENT AT EL ORO
57
' i'. z':^M!:4i^mim^'m'^--2'^'tmm:^i:
■n^
':>
•
I ■:
^ «
i
1
> !
58
AMONG THE MINES OF MEXICO
1. Mechanical handling of the ore.
2. Heavier stamps.
3. Re-grinding in tube-mills.
4. Mechanical handling of sand by distributors,
excavators, and belt
5. Mechanical agitation of slime by stirrers and
centrifugal pumps.
The new mill contains 100 stamps, each weighing
1,180 pounds, falling 102 times per minute, with a
6-inch drop. The depth of discharge is 2>4 to 3
inches with a new die, and 3>4 inches when the die
is worn out. Woven brass wire screens of 35 mesh
are used.
Th- accompanying diagram" (Fig. 7) illustrates
the process. From the stamps the crushed ore goes
to a system of cone-classifiers and spitzkast .1, which
separates the coarsest sand and sends it to the tube-
mills for re-grinding. The fine sand from the stamps
combines with the similar product from the tube-mills
and is elevated by the raff-wheel to the sand-collect-
ing vats. Any slime that may have escaped com-
plete separation and accompanies the sand, overflows
from these vts and passes to the slime-plant, joining
with the rest of this product that has been eliminated
from the sand by the classifiers. The sand is dis-
!i
• Borrowed by permission from 'The Grinding of Ore by Tube-Mills,
and Cyaniding at El Oro, Mexico,' by G. Caetani and E. Burt. Trans-
actions American Institute of Mining Engineers, February, 1906. This
is a conscientious and most valuable paper, giving a detailed account of
the cyanide practice at El Oro.
-^^S"^^^
MECHANICAL DEVICES
59
tributed by a revolving irn jhanism of the Butters &
Mein type. There is no chemical treatment in the
sand-receiver, the idea being to keep the mill-water
free from cyanide while effecting a final separation
of slime, so as to get a clean product. The water
and slime are drawn off through gates or slots on the
side of the vats; these gates are closed by a roll of
canvas as the vats fill. The sand, when thus finally
freed from the last trace of slime, is removed by a
Blaisdell excavator, which drops it through a central
opening onto a Robins belt-conveyor. This Blais-
dell excavator s like a revolving disc-harrov; and it
has proved a most efficient machine, it uses com-
paratively little power and works smoothly. The
belt-conveyor takes the sand (containing now only
from 10 to 11% moisture) to the treatment-vat, which
is fed by a revolving distributor operated by a
variable-speed nriotor, the centrifugal force being so
regulated as to throw the sand to the sides or centre
of the vat, as required. The charge is 265 tons, dry
weight. Ten washes of alternately medium (0.1%)
and strong (0.2%) solution are introduced, six hours
apart. This treatment is followed by no less than
thirty 'weak' washes, such a lengthy operation being
specially designed to extract the silver. These
'weak' washes are four to six hours apart and contain
0.0.3''O cyanide. Each wash is equal to 13 tons of
solution. After treatment, the residue, again using
the Blaisdell machine, which moves on rails, is dis-
f:m^
::'Qi^-
6o
AMONG THE MINES OF MEXICO
charged onto a conveyor that takes it to the dump.
Here the distribution of tailing is regulated, as the
accumulation grows, by a hinged belt-conveyor in
two lengths, the last one being swung round accord-
ing to the contour of the ground.
iih'iiti^^
i»i
liii
f
,i .
J (
. ^
i
3
t-
J
P
1
i
(
CbopUr 10
TREATMENT OF SLIME— USE OF LEAD ACETATE-
ADDITION OF LIME — ITS DOUBLE FUNCTION —
SETTLEMENT OF THE SLIME — THE TUBE-MILLS -
THEIR LINING — SUCCESSFUL WORK.
HE slime goes to a collecting
vat, from which the thick mud is
drawn oflF at the bottom and
thrown into one of the treat-
ment-vats. There are twelve of
^,.v these, each 34 feet in diameter
/^ and 12 feet deep. Here it is
agitated with a proper propor
tion of cyanide solution, which is introduced simul-
taneously. The apparatus for stirring consists of two
long and two short arms made of oak. These are
solid; they taper outward from a cross-section of
4 by 6 inches to 4 by 4 inches. The thick end is
bolted to a steel star, which is set on a ^'ertical shaft.
When the vat is charged, lead acetate is added imme-
diately. Tests have shown that a beneficial result
ensues forthwith, particularly as regards the disso-
lution of the silver.
Lead salts, when added in excess to the cyanide
solution, give a precipitate of basic lead cyaride, but
when present in small proportion the lead remains
in solution, presumably owing to the formation of
yfl
6a
AMONG THE MINES OF MEXICO
U t
an alkaline plumbite (K,PbO,) by reaction with the
caustic alkali, thus:
PbAc, + 4KOH = K.PbO, + 2KAc + 2H,0.
Mercuric chloride is sometimes employed for the
same purpose, producing a reaction with the KCy
so as to form a soluble double cyanide, thus :
Hga. + 4KCy = K,HgCy, f 2KCI.
The most useful effect of these soluble lead and mer-
cury compounds is the removal, m the form of in-
soluble HgS and PbS, of any soluble sulphides that
would otherwise retard the solution of gold and silver,
and might even re-precipitate silver already dissolved :
K,S -I- K,HgCy. = HgS + 4KCy.
K,S -I- K,PbO, + 2H,0 = PbS + 4KOH.
The double mercuric-potassium cyanide also acts as
a solvent, attacking gold more readily than simple
KCy; and this action is independent of the presence
of oxygen, gold replacing mercury :
K^HgCy, -f- Au = KjAuCy^ -f Hg.
Silver is similarly dissolved. These reactions have
been amply verified. The action of mercurc-potas-
sium cyanide on gold is the basis of patents secured
by Keith and Hood; the latter also claims the use of
lead as facilitating the solvent effect of cyanide solu-
tions. De Wilde has a patent involving' addition of
lead oxide to the cyanide solution. These compounds
also influence precipitation beneficially if they remain
in the solution up to the point of entering the zinc-
box, as in that case the lead and mercury are precipi-
tated on the zinc, forming zinc-lead and zinc-mercury
i if
CHEMICAL EQUATIONS
^
CO tples of high electro-motive force. In this precipi-
ta« on the zinc simply changes places with the mer-
cur. or lead, as is also the case when zinc shaving is
dipped in lead-acetate solution.
The charge is 60 tons (dry weight) of slime; this
is mixed with a solution in the proportion of 2>^ solu-
tion to 1 of slime, by weight. The solution contains
0.05% cyanide.' Agitation continues for six hours
The vat is then filled until there is Sj/i of solution to 1
of slime; this is well stirred and then allowed to settle.
Settling and decantation consume eight hours. This
part of the process is hastened by the use of lime,
which is added to the feed of the tube-mills.
The lime has two functions, one of them chemi-
cal, the other physical. By virtue of the first it neu-
tralizes the sulphuric acid and decomposes the ferric
sulphate contained in the ore, and due to oxidation.
Such oxidation may have occurred in parts of the lode
before it was mined, or it may have been developed
by subsequent contact with the air in its passage to
the mill or during treatment. The lime serves in this
way to protect the cyanide of potassium or sodium,
as the case may be. In slaking, the calcium oxide
(CaO) takes up water to form the hydroxide
(Ca(0H)2), which dissolves in wat?- to the extent of
one part in 800. Lime is preferable to caustic soda,
'Sodium c>anide is used, but all calculation? are made in terms of
the cqmvaUnt potassium cyanide. lOU lb. NaCy is equal to 128 lb KCy,
"?5,"''^^' '" practice eight-tenths of NaCy does the work of one unit of
NCy. I he chemical action is the same, the lesser freight on the more
cncentrated form of the cyanide making the sodium preferable to the
potassium salt. j- v iw
'Jv-
■f I
.V «
u
64
AMONG THE MINES OF MEXICO
for this particular purpose, because the calcium car-
bonate is in'ioluble in water, while the sulphate is but
slightly sol'.'ble, so that they do not accumulate in the
cyanide solution, as is the case with the correspond-
ing sodium salts where NaOH is used as the neutral-
izing agent. Soluble carbonates are also precipitated
by it, leaving caustic alkali in solution, thus:
CO3 -(- Ca(OH), = CaCO, + Ufi
NajCO, -I- Ca(OH)j = CaCO, -|- 2NaOH.
By reason of its physical function in the mill, lime
coagulates slime, so as to cause settling of the parti-
cles. The effect is complex. Much of the material
classed as slime is of a colloid nature; indeed, slime
has been recently labeled a 'colloid hydrate.' Such
matter when brought into contact with pure water
becomes almost gelatinous, and therefore impervious
to solution. There are several substances, notably
alum, acids, soap, and lime, that, when added to the
turbid water, cause the gelatinous matter to coagu-
late or flocculate, so as to produce a separation into
distinct agglomerations. Further, minute particles
of ore, whether slimy or not, if suspended in water
and refusing to settle, develop a tendency to subside
when lime, alum, and other substances are introduced.
Although imperfectly understood, these reactions are
used largely both in metallurgy and in agriculture.
The slime settles rapidly; within two minutes
there is an inch of clear water. Then the clear solu-
tion is decanted and passes to a filter-vat, the bottom
of which is provided with two or three feet of sand
■
^^
^
V
■h
i
TUBE-MILLS
65
on the top of burlap. This removes any remaining
trace of slime, cleaning the solution so that it is fit
to go to the precipitation-house.
Returning to the treatment-vat; the slime re-
maining after decantation undergoes further agita-
tion. The vat is filled with a 0.03% solution and agi-
tation ensues for 1^ hours. Then follow three more
successive washes. The vat is then filled for the fifth
time and the mixture is thrown by a centrifugal pump
into a deep settling-vat. Five of the treatment-
charges go to one of these vats, of which there are six,
each being 20 feet deep and 34 feet in diameter, with
a capacity of 450 tons. The successive charges from
the treatment-vat are fed into one settling-vat until
it is full of slime, for as fast as the solution gathers
on top it is run ofif, just sufficient time being given for
clarification. This clarified solution is so poor in gold
and silver that precipitation is not attempted, the
solution being used as the first of the washes in the
treatment-vat.
The new mill contains three tube-mills. All of
them were made by Krupp, at Essen. The No. 3
mill is 19 ft. 8 in. long with 3 ft. 11 in. diameter; No. 4
is 4 ft. 11 in. diameter, and 23 ft. 9 in. long, while No.
5 is of the same diameter as the last, but 26 ft. 3 in.
Iiing. The smallest of the tubes is found to do most
work per horse-power required. In Western Aus-
tralia the tubes or grit-mills (as they are often called)
have been cut down to a length of 13 feet, but the ore
at Kalgoorlie is softer, so that grinding is more
( 1
!'
66
AMONG THE MINES OF MEXICO
quickly accomplished than at El Oro. The time re-
quired is determined directly by the hardness of the
rock, for the ore is fed at the upper end and makes
its exit at the lower, through a screen. Of the three
types of tube-mill, the Abbe can be filled more than
half full; this cannot be r1 ->ne with the Krupp mill be-
cause it both fills and discharges at the centre. The
Davidsen has central feed but peripheral discharge,
while in the Abbe mi's this is reversed, the feed being
peripheral and the discharge central. The last men-
tioned is built in divisions and the driving is done on
tires and by gears, which circle the exterior of the
shell, like a Bruckner furnace. The Krupp tube is
made of wrought-iron sheets, welded ; it runs on trun-
nions placed at one end, so that the shell does not
come into play as regards the driving of the machine.
The lining of tube-mills is an important matter.
Chilled cast iron, both that imported from Krupp's
works and that made by the El Oro company itself,
has been tried ; the latter costing one half the former
and giv* g equal wear weigh t-for-weight. Krupp's
lining is from Ji to I inch thick; El Oro lining is
Ij^-inch thick. Nevertheless, it is the intention of
the manager' to substitute silex, a natural flint with
characteristic conchoidal fracture; it is whittled into
shape in Germany before shipment, arriving in pieces
Zyz to 4 in. thick, 4 in. wide, and 6 in. long. The peb-
• Robert M. Raymond, to whom I am indebted for much valuable
information, and for a persona! kindness it is not possible adequately to
acknowledge.
LINING OF TUBE-MILLS
67
bles that do the grinding come from the coast of Den-
mark. They vary in size from that of an egg to that
of a fist, the average being about three inches in
diameter. They w^ear well, six pounds of pebble being
abraded during the grinding of one ton of sand; the
consumption of lining being 1.6 pounds. [Since then
the abrasion has been decreased to one pound per
ton of sand.] An attempt is being made to select
some of the flinty quartz, such as occurs in the low-
grade ore of the mine, to serve as grinding material.
This seems wise; if the hard portions of the ore can
be used to grind the soft, the economy is obvious.
[According to later advices, this was not a success,
I also learn that the lining of silex has been discarded
in favor of bar plates.]
At the time of my visit. No. 3 tube was being
driven at the rate of 31 revolutions per minute, while
No. 4 and No. 5 made 29 revolutions. The duty of
the individual tube-mills cannot be stated; 172 tons
of the coarsest sand from the new 100-stamp mill is
re-ground from 35 mesh to 150 mesh, or finer, by the
three tubes. In addition, 85 tons per day of the
coarsest of the 40-mesh sand coming from the old
100-stamp mill is reduced to the same condition,
making the total work of the three tubes 257 tons.
The tube-mills get everything above 150 mesh,
as separated by classification in cones. The aim is
to grind to 150 mesh and this is accomplished as
nearly as the capacity of the plant will permit. Any
oversize is returned — as already described — to be
H-
\
i
i '..
ft-'
68
AMONG THE MINES OF MEXICO
re-ground. The cyanide treatment is based on mak-
ing a product of sand as nearly 150 mesh as possible,
while the 200-mesh pulp and finer are treated as slime.
This tube-mill practice has steadily gained in im-
portance, the tendency being to treat a larger propor-
tion of the product from the stamps and to augment
their crushing capacity, while enlarging the cyanide
annex. This is a proper way of meeting the neces-
sities of a mine the output of which increases in ton-
nage as the assay-value declines.
The following statement of the work done during
the month previous to my visit explains itself:
REPORT OF CYANIDE DEPARTMENT, SEPTEMBER, 190S.
Mill No. 1.
. Gold . . SiWei •
Assay* Indi> Atsiy. Indi-
value cated value cated
Claasificatioii. Tons per extrac* per extrac.
treated. ton. tion. ton, tion.
% $ % $ %
Coarse Sand ...29.23 2,552 9.46 54 33 1.73 27.17
Fine Sand 25.57 2,233 7.86 72.14 1.57 45.86
Slime 45.20 3.947 9.04 93.58 2.03 82.26
Total 100 8,732 8.86 76.50 1.83 58.99
The old mill was built before re-grinding was adopted. The fine
sand is poorer than the coarse because it contains less gold open to attack.
The slime is richer in silver because of the presence of argentite.
Mill No. 2.
% Tons. $ 7c $ %
Sand 24.12 2.527 8.28 83.94 1.59 65.41
Slime 75.88 7.949 7.68 92.45 1.64 78.05
Total IOC 10,476 7.82 90.28 1.63 75.08
The new mill includes a systematic scheme of re-grinding, as shown
by the increased proportion of slime. A better extraction on slime raises
the general result to a satisfactory figure.
!| I \
Cyaniue-Vats ami Taii.inc.-W !f.F-L
jiI
I.
i ^
. M
is !
Mi
chapter U
FURTHER NOTES ON EL ORO PRACTICE — THE
STAMP-MILL — MORTARS AND GUIDES — APPA-
Ri\TUS FOR SIZING -THE PRECIPITATION HOUSE
-FILTER-PRESSES — RECORD CF TESTS.
FEW scattered notes on the El
Oro mill may be worth record-
ing. The bolts of the battery-
frames are coupled by washers;
these are 6 to 10 inches long and
from 2^ to 3 inches wide; they
connect two bolts and hold them
firm. If one gets loose, the other
holds it in grip and prevents movement. The ac-
companying photograph* of the interior of the mill
will aid the description.
The guides are made at the company's foundry,
of cast iron; instead of being sectional, with bolts,
they consist of one solid piece. Each stamp has its
own guide and a right-angle plate, to keep it in proper
place and line. The wear is slight and therefore the
stamp works smoothly; there is less heating than
with wooden guides.
The mortar is a development of the anvil-block.
This is an excellent mode of construction, if properly
done. I know of one case — not in Mexico — where
'For many of my photographs of El Oro I am indebted to Mr
Alexander Anderson.
I i'
II
70
AMONG THE MINES OF MEXICO
f !H
trouble was caused by the an.il-block being con-
structed so that it did not rest perfectly true on the
cement foundation; to remedy this, it was the custom
to shim the concrete block with a little cement; when
this last broke and crumbled, there was a movement
of the mortar itself. At El Oro, the mortar-block is
made extra heavy, beet ning to some extent an anvil
in itself, with a base three feet wide and a bottom 13
inches thick; this is placed upon a concrete founda-
tion, with a piece of quarter-inch rubber belt between.
At El Oro, cones are superior to spitzkasten;
the sizing tests have proved this abundantly, the
separation by the cones being much sharper. The
circulation and agitation of slime are aided by six
pumps, which are the Butters modification of the
Gwynne pump, such as is used in the London dock-
yards. They are of the c. .itrifugal type ; compressed
air is introduced to effect aeration of the solution.
The chief advantage of t»"j Butters modification is
that all wearing parts are readily removable. Each
pump makes 1,300 revolutions per minute and in
that period handles 4>^ tons (SYi tons being solution)
of slime.
The vats are all made of steel plates, A inch
thick on the sides, with 34-inch bottoms. Redwood
laid down at El Oro comes to the same cost, but the
steel is more durable and makes a tighter vat in a
climate such as that of central Mexico. The vat does
not dry if empty, there are no staves to check, and
there is no absorption of solution.
m
ZINC SHAVING
7»
In the precipitation-house, there is used a device
introduced independently by W. K. Beity in South
Africa and by Alfred F. Main at El Oro;* I refer to
a drop-drip of cyanide {lyzVv solution) over the head
compartment of each zinc-box that is precipitating
from the weakest solution, namely, the one coming
from the treatment of slime. This drip makes the
zinc more active, so that a precipitation of precious
metal is obtained in a manner usually unattainable
from so weak a solution, that is, one containing only
0.02% KCy. Still weaker solutions are successfully
precipitated in which the quantity of cyanide is so
small as not to be detected by the ordinary silver
nitrate test.
The method of dipping the zinc shaving in lead
acetate (to aid precipitation) is not employed at El
Oro because lead acetate is used at another stage of
the process, as already explained. Zinc fume was
tried, but it was ineffective with such weak solutions.
Great care is taken with the zinc shaving, to cut it in
thin but tough filaments, not so crinkly as to break
easily in handling. The shaving is laid in the boxes
most carefully, so as to avoid channeling. The El
Oro plant is the only one of its size where acid treat-
ment is not used. From the boxes the zinc is sent
through launders, to be carefully screened, while it
is also being washed with fresh water. Then it is
pumped into two filter-presses until they are full, the
* .Mr. Main is assistant manager for the El Oro Mining & Railway
Company.
=7:^R5?tP«'5-,
I
i
i:
1 ■
t
\
{' i
i '
i
.
'it 'i
7»
AMONG THE MINES OF MEXICO
charge being equivalent to 19,000 ounces of bullion.
The effluent solution is returned to the sump, the
cakes in the press are washed and then dried by
steam, the steam heating the iron of the frame suffi-
ciently to dry the cake inside. The cakes are dried
to such a consistence as will facilitate fluxing before
briquetting; they fall into a car and are then mixed
with the fluxes needed for melting; the mixture is fed
into a briquetting machine, making round bricks Syz
inches thick, 3 inches in diameter. These are dried
before being thrown into the melting pot, from which
bars of 1,000 ounces are cast. The Mexican work-
men are compelled to remove their clothes after work,
before passing to the outer room. The precipitation-
room has a cemen*^ floor and the furnace has a dust-
chamber.
The development of milling at El Oro em-
phasizes the relative import e of the cyanide
annex in the modern wet treatment of precious-
metal ore; the annex to the new mill required an
expenditure a little more than twice the cost of the
new 100-stamp mill itself. The tendency is to in-
crease the percentage that is re-ground, the perfec-
tion of the extraccion being largely dependent upon
the fineness of comminution. At the time of my visit
the aim was to make two products; sand, as near 150
mesh as possible (and a decreasing percentage even
of that) and slime, that is, all below 200 mesh. Of
course, sand, even when re-ground, is different from
clay, despitj equality in size of particles; the grains
I -^. " .1^ Wt-M- I
SIZING TESTS AT EL ORO
7i
of 'sand' are sharp as against those of a mud (slime)
rendered impalpable by absence of sharp edges.
'Sand,' however fine, filters well, while 'slime' will not
filter at all ; it packs like glue. On the other hand, by
reason of the relatively larger surface presented by
minute particles, chemical action on the precious
metals in 'slime' is almost instantaneous. How
neceF"ary re-grinding is, was shown by a simple ex-
periment made by Mr. S. H. Pearce. Sand, after
ordinary cyanide treatment at the old mill, where
there is no re-grinding, was dissolved in aqua regia,
but the 'purple of Cassius' test, with stannous
chloride, gave no precipitate whatever, the gold being
effectively locked within the grains of quartz. The
assay of the sand gave $4.50 per ton. Hence the need
for re-grinding.
The accompanying record of tests will prove in-
teresting to those engaged in cyanide work. Look-
ing at Fig. 8, it will be noted that the legend explains
the graphic representation of two sizing tests. At
the time of these tests, a 2j^-inch chuck-block was
used, but it was too low to have much effect on *he
degree of fineness of the product; during the test the
stamp-discharge was as through 28 mesh. Under
these conditions the load on the tube-mills and on the
plant became too heavy, so that finer screens were
substituted shortly afterward. In the diagram (taken
from the paper by Caetani and Burt, already men-
tioned) the ordinates represent the size of the screen
and the abscissae the percentage retained on each of
-»!'
'I;
.\:.;().\(; the mines of Mexico
EXTRACTION FROaI SAND
75
the screens. In the legend, "Thro' 250 mesh" should
read "through 200 mesh."
The use of the term 'sand-index,' to be seen in the
note appearing on the diagram, requires explanation.
Cactani and Burt employ it, and it represents one of
the most valuable features of their paper. The prob-
lem may be stated thus: Given two sands of the fol-
';)wing analysis:
Mesh On 20 On 40 On 100 On 200 Through 200
On 20
% 7o %
ht sand 10 30 25
2nd sand S 15 45
5
15
or slime
30
20
Which of these two sands is the finer? Caetani
answers the question from the economic point of view,
thus'": It is desired to know the fineness of a sand for
the '.ason that the finer the sand, the better the ex-
traction obtained. Therefore the maximum possible
extraction on a sand of given composition is a number
proportional to its fineness, considered from an economic
standpoint. As at El Oro the metallurgist can a priori
calculate exactly the extraction from a sand when a
sizing test has been made, therefore he can calculate
the index and represent thereby with one number what
would otherwise have to be indicated by a tabulation
consisting of 14 numbers. In the examples quoted at
the beginning of the paragraph, the second sand is
finer than the first, although it contains less slime.
" In a letter to the author.
C^apUr 12
THE MILL OF THE ESPERANZA — USE OF HUNT-
INGTON MILLS — TREATMENT OF SAND — NO
AMALGAMATION — EXTRACTION.
I*
I (i
HE Esperanza mill had 120
stamps when the present com-
pany took it over, in 1904. It
was deemed advisable to in-
' crease the capacity at the least
possible cost, so 15 Huntington
mills (each of 5-ft. diam.) were
, added, with the idea of re-grind-
ing before cyanidation. This was tried, but it was
found necessary to place the Huntingtons above the
stamp-batteries, which necessitated elevating the
pulp. It being difficult, therefore, to distribute the
pulp to the Huntington mills, it was finally decided
to use the latter machines for first grinding, in asso-
ciation with, instead of in succession to, the stamps.
The crude ore passes over a lJ4-inch grizzly be-
fore it reaches the rock-breakers; after being crushed
by them, the ore goes over a ^^^-inch grizzly, the un-
dersize being allotted to the Huntingtons and the
oversize to the stamps. The batteries are provided
with 60-mesh screens; while the pulp issuing from the
Huntington mills goes through an angle-slot screen
i"a
■l!
Ill
THE ESPERANZA MILL
n
equivalent to 60 mes' "tily 65 per cent of the product
■will pass 200 mesh.
Of the 15 Huntingtons, 6 are now used as first
grinders on low-grade sulphide ore, the product be-
ing sized and distributed to 6 Wilfley tables, the tail-
ing from which, after classification, passes down
blanket-sluices before finally reaching the cyanide-
vats. The concentrate from the Wilfleys and that
washed from the blankets, goes to the smelter at
Aguascalientes.
The other nine Huntingtons treat oxidized ore,
which, after being ground, goes to the cyanide annex.
The cost of steel and repairs to wearing parts amounts
to 34 centavos per ton; labor averages 15 to 20cv. per
ton. The muUer-shells and die-rings are made of
rolled steel manufactured by the Midvale Steel Co.,
of Philadelphia. This is a soft metal and is suscepti-
ble of being kept to shape; it can be used until worn
out, and is, therefore, economical. Each Huntington
mill has its own motor; it has proved itself to be the
best n.achine for reducing the ore to a certain point
—say, 60 mesh — beyond which, for finer grinding, it
is not economical.
The sand undergoes treatment for 100 hours;
for it is found that extraction ceases then. Aeration
is effected by a perforated pipe discharging over the
return-solution vat; yet there is no such loss of cya-
nide as might have been expected. The former col-
lecting-vats are now used for treatment ; there is less
aeration and less mixing, but there is a great gain in
;8
AMONG THE MIXES OF MEXICO
the capacity of the plant without interference with
effective percolation. A vacuum-pump, for with-
drawing the enriched solution, is used only at the
close of the operation. Sodium cyanide, NaCy, is
the chemical employed; it is guaranteed equal to
1257c active KCy, ranging from 124 to 128 per cent.
The enriched solution, before precipitation in zinc-
boxes, is rarely higher than $2.20 in gold. Fresh cya-
nide, in crystals, is added to the heid of the zinc-
boxes, sometimes in quantity suffir!ent to keep the
solution up to standard strength.
There are no amalgamating plates, and no mer-
cury is used in the Esperanza plant. This is an inter-
esting divergence from El Oro practice.
During September, 1905, the output of the mine
consisted of 5,280 tons of shipping ore and 12,00J tons
of milling ore, having together a value of $780,385.
The extraction in the mill was 91.64 per cent of the
gold and 52.92 per cent of the silver in the crude ore.
At this time the Esperanza was the most pro-
ductive gold mii.e in the world, the two ranking next
being the Simmer & Jack, with a monthly output of
$505,000, and the Robinson, with $450,000; these two
mines being in the Transvaal.
d)apUr 13
MIXING METHODS IN THE EL ORO MINE — DIA-
MOND-DRILLING IN THE ESPERANZA— TIMBERING
BAD GROUND — PRECAUTIONS TAKEN — LAYING
OF TRACK — EXCELLENT SYSTEM.
O time is wasted in handling ore
from the El Oro mine. At the
main (incline) shaft there are
two gyratory (Comet D) crush-
ers, the oversize from which
goes to a jaw (Reliance)
breaker, 9 by 15 inches. Thence
the ore passes into bins and
from them it is fed onto a (Robins) belt-conveyor,
which is made in divisions as demanded by the
length (about 200 yards) and the slope to the
mill. At the mill the ore is delivered by the
conveyor to a traveling tripper which distributes
it automatically into the bins; the tripper moves over
the bins the entire length of the mill and then returns.
When opening up ground previous to stoping, it
is the custom to run a main drift in the middle of the
hanging-wall orebody, leaving ore on both sides up
to the top of the timbers constituting the drift-set.
Then stoping begins above the drift for the full width
of the orebody. When the ground begins to weaken
and re-timbering has been carried as far as practic-
80
AMONG THE MINES OF MEXICO
able, the slopes will be about half-way up to the next
level; then the drift in the foot-wall orebody is
utilized, by driving cross-cuts from it to the hanging.
These tap chutes wherever practicable, but if the
ground near a chute has caved, then a new raise
(from the lateral drift) is made to serve the purpose
of extracting ore. Finally, when even the foot-wall
begins to be bad, a lateral drift is run in the foot-wall
country itself, and this sometimes leads to unsus-
pected occurrences of ore.
Another procedure is to leave about twenty feet
of ore above the top of the hanging-wall drift; the
arch of ground being removed upon the final extrac-
tion of that block of ore. This method is employed
when the maintenance of a roadway is vital, especially
when approaching a shaft.
It is instructive to note that while the operating
expenses at the Esperanza during 1904 represented
74 per cent of the production, after the bonanza was
struck the proportion of expenses decreased to 37
per cent. The diamond-drill cut the new West vein
in August, 1904, and the discovery was mentioned by
Mr. R. T. Bayliss at the El Oro annual meeting in
October, 1904, but the big rise in Esperanza shares
did not begin until the spring of 1905. The story of
the discovery illustrates anew how deceptive a single
cross-cut can be. The West vein was cut by a cross-
cut on the third level at a point 150 feet north of the
south boundary of the nrne; the ore was poor, about
15 inche'- of stufif rssaying 17 grams of gold per ton.
11
THE ESPERANZA BONANZA
8i
Next it was intersected in a drill-hole 900 feet north
of the place just described, but on the fourth level.
Here also it was poor, aL^at 18 inches, assaying 12
grams. This was done by the former Mexican com-
pany about four years before the eventual ascertain-
ment of its real value. In August, 1904, the drill-hole
put out by the new management, at the fifth level, cut
the northern portion of the orebody and found 22 feet
of an average value of ^37 per ton. But the cross-cut
which was started at once on the track of the hole cut
an 11-ft. vein assaying $75, the probable explanation
being that the drill followed a cross-stringer connect-
ing a poor vein, 5 feet thick, to the 11 feet of rich ore,
there being 6 feet of shale between them, so that the
22 feet of core assayed $37 per ton.
The discovery is creditable to the management,
as it was owing to their good judgment in the use of
the drill. Now two drills are kept in constant use,
although this manner of testing the ground is expen-
sive, because the hard quartz abradcL the carbons.
The average cost is five pesos per foot of J^-inch core.
A Sullivan E drill is used, capable of drillmg 400 feet.
In the Esperanza mine, it is the custom to ex-
tend main drifts in the ore, which is hard and stands
well. Although the shale is softer, it is found eco-
nomical to keep within the vein, because this practice
obviates timbering as the drift progresses. When
the drift has been advanced the desired length — a
month's or even two months' work, at 65 to 70 feet
per month — the ore is taken down on both sides and
I
f .1
i>'
82
AMONG THE MINES Oi- MEXICO
double drift-sets are put in place. When mining near
the big fault, skillful work is required. On the upper
levels the shattered ground is narrow, but this evi-
dence of faulting increases in depth, so that while it
is barely one foot wide on the first level, it is 20 feet
I ill
Fig. 9.
wide at the fifth, where it is dangerous. In order to
traverse this ground, not only is 'spiling' required on
top, but also on the side of the drift. The set is put
in place in the customary manner, with cap,
blocking, and 'bridge,' so that it looks like
Fig. 9. The 'bridge' serves as a resting place
i t
,1
METHODS OF TIMBERING
83
I ■
84
AMONG THE MINES OF MEXICO
I I
i 11
for the spiling poles and allows space under-
neath for driving. Pointing the spiling up-
ward and sharpening it from one side, tends to lift the
soft rock. When the spiling has been pushed on top
and at sides, it is driven either with a sledge-hammer
or, if that is ineffective, with a ram. If the roof-
spiling needs this treatment, the ram is put on rollers.
This ram is a piece of 8 by 8 inch timber, from 8 to
10 feet long, so as to get a good run with it over
rollers; if it is to be used for driving spiling near the
floor, the ram is suspended from a roof-timber and
thus it gets a swing. If the ground commences to
run, the face is bulk-headed with 4 by 12 or 6 by
12 ir planks, according to conditions. These
breast-boards are then blocked by spiling, both on
top and sides. The next step is to advance them.
If the bottom one is advanced first, the ground would
run, but if t^.ie top one is pushed, there is nothing to
escape, because the top spiling holds it back. There-
fore, two jack-screws are brought to the spot and
they are placed with heel (or base) on a cross-timber
carried by the rear set. The top breast-board is now
advanced 8 or 12 inches and a sawed-off block is in-
serted within the space thus obtained; this block
holds the breast-board in its advanced position. The
next board is pushed to a corresponding position, as
before; the cavity made is cleared, the soft ground
being taken out over the top of the next lower board.
This procedure is repeated with the other boards
until they are all in line, marking a permanent
li I
J ;
MHB
M^i'mim.
i
TIMBERING IN BAD GROUND
85
advance of 8 or 10 inches or more, as circumstances
permit. This is position No. 2, as shown in Fig. 10.
On the next advance, longer blocks are used to keep
the breast-boards in place and the work goes on until
room has been made for another set. See Fig. 1 1.
The north shaft is sunk through bad ground,
j)articularly a length of 200 feet between the third
and fourth levels, and another stretch from the eighth
to the ninth. There is a creep of 15 inches per an-
Fic. 12. Special Shaft Set; 14-In. Timbers.
num, and it is found necessary to renew the timbering
every nine months; this is done by a gang of peones
si)eciallv trained under a Piedmontese foreman. See
Fig. 12.'
Double sets are used for timbering main drifts;
all the caps are double-locked to prevent splitting
and, in rare cases, even the sills are double, when the
ground underfoot tends to rise. In such cases an
\i
U\
■J
t
^■m
ii if
86
AMONG THE MINES OF MEXICO
Fig. 13. Square Set. 8-In. Timbers. Plak and Elevation.
; !
, i
SQUARE SETS
87
I
I -r m WSSr.fJ
«
■SO
4 -*
4 6
■c Vf-
W
\.i.
re'
Fig. 14. Squahe Set. 8-In. Timbers. Side Elevation and Details.
<^^^'^.
AMONG THE MINES OF MEXICO
4
! !■
I
ji .!
li
intervening block of ten inches is inserted, the bottom
sill being the first to break. Ordinary sets would
last only 60 days, the double sets are in service for
12 months; the top set takes the weight and yields,
without interfering with the use of the drift. The
lower set remains unimpaired, until finally it is
pushed too hard; then the pressure is opposed by the
erection of a false set, which, while the lower set is
being replaced, does service as a top set.
In bad ground it is the custom to leave from
three to four inches between the lagging, so as to
permit the soft ground to come through, but not
enough to block the tram-track. After this the
ground is n<- . cased further until the lagging breaks;
it is then leplaced by fresh poles. li the weight is
from overhead, no effort is made to ease the pressure,
which is allovv'cd to break the timbers, to be replaced
by fresh sets. The choice is between losing time in
cleaning the track or letting the timber stand as long
as possible before renewal. It is held that the ques-
tion of blocking the track is paramount in a mine pro-
ducing so large a tonnage of rich ore.
Where it is the intention to encourage the
ground to get relief of pressure by pushing through
the lagging, the space between poles is six inches.
Close lagging requires more frequent renewal, but it
eases the timbers. By allowing the side of the drift to
break through, more weight is thrown on the timbers,
by the enlargement of the arch of ground overhead.
Stope-sets are five feet from centre to centre,
SYSTEM OF TRACK-LAYING
89
with a height of eight feet. They are so placed as to
oppose the tendency of the walls to close, and the
consequent strains are all accepted on the end of
timbers. See Fig. 13 and 14.
Great care is taken with the tracks and ad-
mirable system is exhibited in the arrangement of
them. The cars weigh 1,100 pounds each and carry
2,200 pounds, the total weight being 3,300 pounds.
The gradient is a half of one per cent, that is, it is
such that the labor of pushing an empty car up-grade
is approximately equal to that of pushing a full car
down-grade. The width of track is 23 inch.s, or 60
centimetres, the gauge being based on the metric
system. The rails are 20 pounds per yard, and of
Carnegie cross-section. The minimum curvature
adopted throughout the mine is a \2-it. radius, for
which standard cast-iron right and left-handed frogs
are used. Switch-points are carefully made in the
Esperanza company's own shops; the points them-
selves being reduced in a planer instead of the cus-
tomary blacksmith shop. All of these precautions
tend to assure easy handling of Iieavy cars by in-
ferior native labor. Special tools are provided for
jending and punching the rails; all curves are laid to
template. The ties are 2 to 2^ feet apart and are
made of 6 by 8-inch timbers. On curves the gauge
is widened lyz inches, and the inside of curves is
protected by a guard-rail ; the same protection is pro-
vided at the points of all frogs. When using hand-
cars, fixed points are l3''1 down; but where electric
ill ■■
1l ]
90
AMONG THE MINES OF MEXICO
(1
a
w
H
(A
i
to
A
HI
SPECIA , SWITCHES
9»
r )|
'm
92
AMONG THE MINES OF MEXICO
II
'! * f •.
-I ;
motors run, the switches are made movable. See
Fig. 15 and 16.
The Esperanza company maintains elaborate
assay-plans. There is one for each floor in the stopes,
the floors being lYz feet apart. On the plan the
timber sets are marked in 5-foot squares ; each month's
work is indicated by a different color, and in every set
the assay-value of each square of ground is marked
in figures indicating grams of gold per metric ton.
There is no assay for silver because the ratio between
the metals is known from experience; in oxidized ore
it is dYz grams of silver to 1 gram of gold ; in sulphide
ore the proportion is as 15 to 1. Every car loaded
with ore from a chute is grab-sampled at the shaft-
station, the assays thus obtained giving the average
value of the mine-output for that day, while the num-
ber of cars gives the quantity. Thus 350 mine-
assays are made per diem, and these also enable the
foreman to keep a check on the kind of ore being
broken. Gangs of samplers, in pairs, test daily each
working face in stopes and drifts; a sampler within
the space of one set will get a chance to test more
than one face, sometimes three of them. Both the
moil and the pick are used; the ore is broken onto
canvas spread underneath; the samples average 50
pounds apiece and are quartered down to 5 pounds
each, before they go to the sampling-room at the
assay-office. All these returns are compared with
the battery sample from the mill.
i I
I /
I'i *
I i
I! f
■'r-^^m^'^wmi^wmr.
' JMa^5or^^¥*:\^K£ii^
Cliof Ur 14
row^R-DOS ES^'A^. iMPOSITION- ELECTRIC
AXES are heavy at El Oro.
They amount, for instance, to 13
per cent on the gross output of
the Esperanza mine, but this in-
cludes State and Federal taxes,
import duties, and the care of
trrops stationed in the district.
... , ^ - On bullion the mine pays 21/, oer
tne btate. All State taxes are subject to a second
r;jzz:' rr ""' ^''^^ ^^^ *° ^^^ ^"-'
m!^TZ "u '' ^ ^^^" *^'^' «° "^"<=h for each
man on the payroll; there is a stamp-tax on every
recorded business transaction; and there are duties
on imports, particularly on dynamite
Th. ?? ^>'"^'".'t« there is a tax of 243 pesos per ton
per month' Th' "p" ''' '''''• °^ '' P^" '« -"'•
cases or ^he Esperanza mine consumes m
weith °K ^ ■? ""f. '" ''^ ^^^^^' «° that the tax
^:;^^eavily. It ,s intended to compel the mining
^^^^^o^i'^^^^^^^^ the Government, and on
removed, while the silver ta"x is r'educej lo'lSt/r cent °" *°''' """ "«"
M
94
AMONG THE MINES OF MEXICO
v't
companies to use the domestic dynamite; but the
Mexican company's factory was blown up twice and
they had ceased to manufacture at the time of my
visit; nevertheless, according to the terms made with
the Government, they had to furnish 607o dynamite
at 19.34 pesos per case of 50 pounds — a rate fixed by
the Government, as against 16.34 pesos, the old price.
While the factory was in operation it cost 29.6/ pesos
to import the explosive from the United States; the
company (Mexican National Dynamite Co.) was
furnishing (in October, 1905) American dynamite for
19.34 pesos, but as soon as their factory resumed, it
was expected that they would sell their own product
at the same price. Americans mining in Mexico con-
sider it to be unsafe and usually prefer to import
dynamite at 29.67 pesos. Recently, one of the lead-
ing companies at El Oro has made arrangements to
buy from the monopoly, which furnishes American
dynamite at about the same price as paid formerly.
The management could not import the American
powder direct, however, without paying the increased
price. The monopoly is allcwed to charge 16.79
pesos for 40%; 18.07 for 50%; and 19.34 for 60%
dynamite.
The electric power used at El Oro comes from
the Necaxa plant, on the river of that name, 176 miles
distant. At the time of my visit the line was nearly
completed. It has been built by Canadian capital.
Mexico City is supplied from the same power-plant,
the distance being 100 miles from the falls to the city
. i|
POWER TRANSMISSION
95
and 76 miles from there to El Oro, over the wi ^s.
There are eight circuits of three wires each between
Mexico and Necaxa, and two circuits, also of three
wires, from the city to the mines. Fifty thousand
volts are delivered at El Oro, by a three-phase sys-
tem, and it is expected that there will be a loss of
eight per cent as far as the city and an equal loss
thence to the mines. The current does not go
through a transformer at Mexico. Power is gen-
erated under a head of 1,450 feet by a vertical-shaft
turbine with the generator on top; the wheel is the
invention of Escher Weiss, at Zurich (Switzerland).
The hydrostatic head at Necaxa has been obtained
by the building of an earth dam, 185 feet high, 1,500
feet thick at the base, and three-fourths of a mile long;
it holds 55,000,000 cubic metres of water and backs
the river 2^ miles. The transmission cable has a
jute core and consists of six strands of No. 6 wire
equivalent to No. 000 wire or 0.229 inch. The power
is sold to the mining companies on a sliding scale, the
prices being graded according to the amount con-
sumed, the lowest price being $50 per horse-power
per annum to those consuming over 1,000 horse-
power. Several times the natives have cut down the
wires and stolen them, on two occasions as much as
a kilometre bein? removed. This has been exag-
gerated by rumoi .o seve i or eight kilometres. As
soon as the cables were . ected, a small current
(generated by a ftteam-plant at Mexico City) was put
on, in order to prevent stealing; the result was that
f.fc,_^jcmi
ill
96
AMONG THE MINES OF MEXICO
Hi
several pectes were killed. Later, when one line had
a ci,r;<nt and the other not, the thieves eemed to
k)3« >* ' rci !?h to distin-^'uish between the «lcad line
ard 'h ; li\ one. The copper stolen > cut up md
S('' 1 ut lis" lunk shops.
')'i<c i-'striUas, or the Two Star is one of the
tii't', T ■ ' ;ni les < El Oro; it IS intt. L^tiusf not only
bcciuse o. J* •. generous production bu' also !)> reason
of 'he roniaiT.'- of its discovery. J. li. Fournier, its
present chit i >' ler, 1- a I'renchman "t education who
prospected the surrounding region with much per-
sistence. He ff uid 'float' (detached lode-stuflf)
where the shale s exposed below the andesite cap
and he found similar indicati('ns also in tlie barr.mca
(or gulch) at the foot of the mountain. Subse
qiiently, he started to work a' 'lie creek-level and ran
a long adit to intercept the vem that he believed to
be there. At a di^^tai e within the mountain of about
2,000 feet he found it and no mistake. It was tue
great Dos Kstrellas lode, Miiich is divided into two
veins, one 3 to 5 feet thick, with rich bodies of ore n
it, and beyond it ; sother vein 40 feet thick ■ f ^2 d
gold ore; the latter i oxidized, but the -ni vein 1-
not, except in patches. Tliis resembles the > aditior
in the Espcranza, where the new West vein small
richer, and unoxidized. while the old Sn: iatael '
wide, poor, and thoroughly oxidized. Fi iruier wa:
lonf,' ago regarded as a crazy man, as ha- been the
case in several similar instances of persist nt pros-
pecting. Thomas Kruse. ^vho discovered tl Drum-
,k1
TME HUMOR OF A CYANIDE PLA T
97
lurnmon K>de, a; .Niarysville, in Montana. v\ rket' alf
alone, i I (■ started to sink i win/' and gave it up ; he
then commenced ro iU^ a 'tunnf for a upposedly
unknown hwJe. ^Vhtn he cut a oig '.idii of '■e, it
-ed. b.
? of
wa consK!
it V IS no*
found an out> rop ,
ni>t : nk a shaft, !>
lull v\ hout a- -ista
incf ii. ihc procec -
:i ^is ■: litarv ' bors,
^\ II the
s in<
ne
ih.
gm 11' as 'tool luck. But
k nd »i<i Tommy Kruse had
k'.K-' that he ah ne couli
i drive .1 drift into '^-e
nd lout *' -' risk of sha
He persisted
lOUt t
.ei
a for
I a cyanide
itio I a cyanide nt may yield
s. note-book bc.onging to one
^^.istant.s was found; u recorded the
'he night shift in the precipitatici-
lai icular fragment rescued from fire
1 true t ions how to pump out the ^^-
and to make rake in the pres
V h ind, had recorded that at a cei
.}) 1; ring — opened press to see why-
chok. i with greasy black substance — r
le — pu- ip worked perfectly." He threw
'he prec Ditate into the old (empty) cyanide-boxes,
ere i was found next day; no damage was done,
lother story is that of visitors being shown over the
li w mill l)y a guide from the iHage of El Oro; he
poi- f'd t the tailing-wheel, wlii:h is 40 ft. 8 in. high,
nv.i lid 'hat it was the wheel that operated the mill,
tnc ors, and everything in sight. This wheel
is ru ,.y wire-ropes; there are two that transmit
luin
of
wor : d
r "m.
c< 'tained
pitate-su
hiiur
fount:
'novc':
mmm
It ii
98
AMONG THE MINES OF MEXICO
!:< ^1
I
ii '
k'i I ft i
movement to the wheel itself, there are four that
drive the first line of agitator-shafts, and there are
two more that go to the pumps; all of them happen
to be close together and doubtless the number of
ropes created the idea that the wheel was responsible
for a great multiplicity of duties.
The only salvation for land titles is due to the
regulation that compels monuments to be visible from
one to the other. By law also it is specified that the
monuments must be permanent stone structures;
otherwise there would be hopeless confusion, for the
records in the mineral-land offices would be unintelli-
gible, because there is no general map and the
boundaries of claims are not referred to any fixed
point or landmark.
The boundaries between the Esperanza and El
Oro mines are marked by posts of masonry plastered
with white mortar; they are set at each corner of a
claim and where the lines are long they are placed at
such intervals as to be within sight from one to the
other. The natives of the vicinity, who thought
they had a squatter's rights to the ground, started to
demolish these monuments, until the company's sur-
veyor marked, with black paint, a cross on each one;
since then they have been reverently left untouched.
Similar superstitious feeling is seen in other observ-
ances. Wherever a man dies — whether naturally or
not — a cross is set up, even underground in the mine;
and each man who passes by picks up a stone, which
is supposed to represent a paper, the equivalent of a
!! f I
-'ii
The Wates-Carrier or Botero
f
ijs
t -'u
«» . -
••> I I
The Ck<i>s nkak the Somera Shaet
Pay-Day at the Casa Blanca, Ei. Oiin
LOCAL COLOR
99
prayer, and drops it at the place so designated. On
the day of the Holy Cross every cross in the country
is decorated with flowers, even artificial ones if others
are not procurable. By the heaping of stones at such
spots, a cairn is eventually formed, serving as a land-
mark. At the place where a priest was killed, near
the Somera shaft, there is an enormous pile of stones,
as is shown by the accompanying photograph.
In the course of a ride on horseback over the
surrounding district, on a Sunday, I observed some-
thing of the life of the people. There is a notable
absence of vehicular traffic; there are no ruts in the
roads, which practically are causeways, worn smooth
by the sandals and bare feet of the peasants. The
paths look as if all the 'weary Willies' in the world
had passed that way. The beauty of the scenery and
the picturesque coloring of the people is spoilt by the
evil smells due to the filthy habits of the peones. At
the close of day, when the tropic darkness comes
swiftly and the air is suddenly cooled, the Mexicans
stalk about silently muffled in their scrapes and with
covered mouth, in order not to inhale the air. It is
a characteristic of the people that they fear the cold
air, largely because they are so poorly nourished as
to be easily subject to pneumonia. With their wide-
brimmed conical hats, the dirty red blanket or the
striped scrape thrown over the shoulder, witii thin
shanks and st'^althy gait, the natives stalk about in
the gloaming through the narrow street like the
brigands of an opera bouffe. There is none of the
' if ' n
100
AMONG THE MINES OF MEXICO
I! !;!
1 .
breezy swing or the cheerful salutation of the Anglo-
Saxon ; nor is this a matter for wonder when one gets
to know the miserable life, the petty tyranny, and the
scant food that is their lot. Cleanliness, good food,
and freedom of opportunity make people more cheer-
ful even in a climate less sunny than Mexico.
Nothing that I saw in Mexico seemed so pathetic
as the conventional acceptance of class distinctions,
especially among the women, the sex usually most
ager to ape the dress and habits of those who hap-
pen to be more favorably placed than themselves.
The lowest class wears blue and brown shawls or
rebosos, the middle class is distinguished by black
rebosos, and the upper class sports the more dainty
mantilla or mantle of lace.
The most vivid impression that I took away from
El Oro was that of a Mexican boy controlling the
operat'-n of a sand-distributor through a variable-
speed i.iotor. The boy's pay was 75 centavos, or Z7
cents per day, and he had charge of two Blaisdell ex-
cavators and the distributor referred to. It was a
picture of mechanical ingenuity overcoming a poor
labor supply, for it was not the skill of the boy so
much as the perfection of the machine that rendered
such economy of operation possible.
III
Cl)apter 15
MINE LABOR — THE CONTRACT SYSTEM — NATIVE
IMPROVIDENCE AND SKILL — DIFFERENCE OF
LOCALITY — POOR HAMMERMEN, BUT WILLING
WORKERS — HOT MINES.
EXICANS take kindly to me-
chanical labor, such as that of
the machine-shop or carpenter-
ing. The average native car-
1 penter, who gets from 2 to 4
pesos per day, is as good as the
white men of his trade that drift
into the country from the north.
Timbermen are fairly satisfactory also; they receive
two pesos per shift. As a rule, the Mexican is clever
with his fingers, as is illustrated in the shaping of
statuettes and in weaving. Guadalajara is famous
for carved images and Cuernavaca for the manner in
which its people mold clay into statuettes and flower-
pots. The assay crucibles used in the El Oro mill are
made locally; so also are the muffles. The crucibles,
sizes F and G, holding two assay-tons, cost only two
centavos apiece and give excellent service.
The ordinary unskilled laborer— such as is re-
quired for carrying material, for unloading, for stack-
ing cord-wood, or in excavating for foundations — is
paid 50 centavos per day, but it is becoming difficult
to get men for such low pay. In a new mining camp
I 1
i t
'\'
i '-f-'
102
AMONG THE MINES OF MEXICO
or on the farm, the day laborer is paid only 25
centavos, while in the north, near the border, he gets
three pesos. This is owing to the proximity of the
American labor supply and the competition between
the mining companies, the wages tending to equalize
despite the international boundary, because both the
northern workmen and the Mexicans go across that
line, to and fro.
Work underground is done on contract as much
as possible; even the trammers and skipmen are em-
ployed on this system, prices being set so that the
miners earn from 1 to 1.25 pesos per shift. In
measuring ground under contract, the unit is a width
of two sets (3.4 metres) of timbers, and the pay is so
much per metre long for the full height of a set (two
metres). Mine contracts are made with each gang of
six men or more, the agreement being arranged with
the two leaders (one to watch the other) ; and these
hire any additional labor such as is needed for remov-
ing rock or tramming. Contracts are measured
weekly, on Saturday night. Wages also are paid
weekly, the surface laborers on Saturday night and
the miners on Sunday morning; this frequency of
payment being due to the fact that the peones have not
enough money to carry them longer than seven days.
On Sundays the market is crowded with vendors of
corn (maize, from which tortillas are made), beans
(the frijoles), vegetables, and fruit. The Mexicans
lay in a week's supply; any money remaining is spent
on pulque. On Monday they are in a demoralized
i Kk i li r
1 y.
■ I.
»?
THE MEXICAN MINER
103
state. Owing to these customs the laborers lo-- vo
days per week regularly, besides an extra 1 .ay
(fiesta) each month. But annoying as thes. . li-
tions are to an energetic management, they are better
than they used to be. Even on local holidays, the
pconcs formerly took three days for their celebration,
while now one day ordinarily wlli suffice. But there
are still seven or eight fiestas in the year when no
pretense of working is made, and operations under-
ground cease. Of course, these national character-
istics of the Mexican do not affect — at least directly —
the American workmen; they are paid monthly, and
appear to be not only sober in their habits, but also
unusually efficient.
In different parts of Mexico the skill of the
miners will vary; at El Oro it is less than at Pachuca.
The cost per ton of ore is not much cheaper than if
done by skilled white miners. Mexicans are not
miners by instinct; as long as they can maul at a face
and detach chips of rock, they will hammer it, instead
of picking it loose or putting in a shot. They are
wretched hammer-men ; a Cornishman watching them
would be inclined to say that it was a "caution," and
the American miner would exclaim that it was a
"fright." They do not appear .0 have any of that
body-swing, when the hand slips over the long handle
of the hammer; instead of this, they have a tight grip
and strike short blows over the shoulder; they will
insist in shortening the handles; nor do they use the
pick where obviously it would bring down loose
m
ilF,
^ .
^- (
i|!i
if*
■:
jj
: }
r 1 r
T]
104
AMONG THE MINES OF MEXICO
ground, but they worry the rock with short hammer-
blows delivered with woodpecker persistence. The
heads of their hammers get into a woeful condition
and their picks are rarely such as a white man would
care to own; in general, they appear to take poor
care of their tools. Owing to their inability to swing
the hammer freely over the shoulder, they cannot
drill an 'upper' and therefore they are not much good
in a raise ; but they are most expert in a winze. At
the south end of the El Oro m.ine, I saw some Mexi-
cans sinking a winze below the 286-foot level and they
were down over 80 feet on a dip of 65°. All the rock
they broke was being carried in sacks on their backs
from the bottom of the winze to the level, and they
were being paid 15 to 20 pesos per metre for a winze
3 feet wide by 6 feet long. In the Mexico mine,
winzes S by 6 feet cost 25 to 30 pesos per metre. The
shift-bosses in the Esporanza mine are mostly Italians
(Piedmontese); they are among the best miners in
the world and learn Spanish readily; in a month they
acquire a working knowledge of the language and
they seem to know how to manage the peones. Most
of the Piedmontese in the Esperanza mine come from
Bisbee, Arizona, simply because the foreman worked
there at one time.
Boys are employed underground for minor tasks,
such as doing errands, carrying -attr, and cleaning
tracks. They are only 8 to 10 :, ^ rs of age. On the
whole, the full-grown workmen .re not well built,
they have the physique of a big boy rather than that
i rf
M
1
• 4 ' 1 ^
m .i m ~
y
m
U
W!^ JJ'V
HOT WORKINGS
105
of a mature man; their strength is all in the back, the
muscles of which have been developed by generations
of burden-carrying. They can transport enormous
loads on their shoulders, but are incapable of carrying
any weight in their hands.
At the Esperanza there are 3,952 men employed;
scarcely three per cent are whites. For some tasks
it is necessary to use four or five Mexicans to accom-
plish what one white man could do, but on other
work the Mexican will do what the white man cannot
do at all, especially as regards carrying loads. The
Mexican will often serve where a mechanical device
would cost more.
When working in the mines the natives are naked
save for a loin cloth and sandals {guaraches), for the
air underground is very warm. On the second level
of the Mexico mine it was 85°; in the shaft (owing to
steam-pipes) fully 1(X)° F. In the cross-cut from the
286-foot level going west from the Somera shaft the
temperature was 95°, and in the cross-cut at 1,086 feet,
it was up to 105°, by reason of poor ventilation and
escaping steam. The general temperature in the
workings is 60° to 70°. The heat is due largely to
the action of water on the lime in the shale — slaking
it — and it may be due also to the crushing of the
shale, which is often seen to press heavily on the
timbers.
At Guanajuato, it is estimated that it takes 2 to
2y2 Mexicans to do the work of one capable white
miner, but the native is paid one-fifth the wages given
D.i
t
^i 1
t I!
S ' 1
. ,:t
1
, :j
lii
■'11
m
io6
AMONG THE MINES OF MEXICO
to the other. The men seen in the mines are under-
sized, they have the physical proportions of an
American boy. In the mountainous regions, as in
Durango, the miners are bigger and stronger, and on
contract work they can earn twice as much as the
Guanajuatenses. Owing to fiestas, it is found that in
employing a gang of peones on such work as excava-
tion, it is necessary to carry 100 men on the payroll
in order to have 30 Iways available, that is, they work
one-third time.
By a town ordinance the miners are compelled
to put on trousers before appearing in the streets.
In coming up or going down a shaft the tanateros sing
alabanzas (or hymns) in rough time; it is a sort of
chanty.
In drilling a 'down' hole, there is no difference
worth mentioning between white and native labor;
the Mexicans strike the drill 100 times per minute,
and their short rapid blows will equal in final effective-
ness the long body swing and harder blow, made
on»-half as fast, of the European or American. The
Mexicans work in less space. I have seen 18 men
working in a shaft 7 by 15 ft.; there were nine pairs,
one man holding the drill and the other striking, the
change of one to the task of the other being made
with the celerity characterizing a drilling contest.
They carry water for the hole in their mouths and
squirt it out as it is required.
Like the Turk, the native Mexican is a great
porter. In carrying weights, the load is hung by a
A STRIKE AT GUANAJUATO
107
rope attached to a head-piece (mecapal), which is a
nearly oval mat made of the ixile fibre; it takes the
shape of the forehead, and reaches down to the eyes,
lying over the front hair and under the hat. The
tarUeros, or ore-bearers, can carry eight arobas or 200
pounds apiece; they will transport as much as that
100 feet up the stone stairways of the old mines. At
the Prospero mine, each man carries four tons per
shift a vertical height of 75 feet, and a length of 400
feet, at a cost of 50 centavos. At Guanajuato I saw
some excavating for foundations done at 25 centavos
per cubic metre, the rock being carried a distance of
200 feet across the gravel of a barranca.
They are good blacksmiths. At the Peregrina
the native workmen took out the flues from a boiler
that was in bad repair; they cut the tubes at both ends,
and welded on an extra piece to make the original
length. One smith and three helpers welded 24 tubes
in 12 hours. The native blacksmiths are good drill-
sharpeners, though better at shaping than at tem-
pering.
Here is the place to tell the story of a strike that
occurred near Guanajuato. Order is not difficult to
maintain in a mining town like Guanajuato, because
the people possess a lively respect for the representa-
tives of the law. The strike at the Peregrina mine
affords an example. In that episode there figured
500 peones; there came four undersized soldiers and a
most unimpressive jefe politico. The paiio was full of
the striking miners, ready for a riot. The little jefe
WB^stsaest)^^^m ■
■,it
M
!f
I li N
\
* if !
io6
AMONG THE MINES OF MEXICO
told the manager to open the patio; the big doors
swung aside; the four soldiers entered with their
muskets clubbed and the jcfe behind them with a
drawn sword. The laborers scattered like rabbits,
the four soldiers whacked all within their reach,
the peoncs fled and fell over the dump; the strike was
over!
The authorities keep a close grip on the native
population. Strikes are rare. They occur occasion-
ally in the cyanide plant, where the men who tram
the sand are inclined to think that they do too much.
El Hro has never had a big strike. Should there be
any disorder or insubordination requiring serious
action, the jefe politko (sheriff) is asked to call out his
ruralcs (police) and these arrange affairs by capturing
the ringleaders, after which the crowd scatters at
once. The peon is an inveterate thief, the mill-hands
steal ore and the precipitate in the zinc-room when-
t'ver possible. When caught in the act, the culprit s
turned over to the jefe politico and in short order the
latter sentences him to serve in the army. He is
made a compulsory soldier and may be drafted to the
hot country of the Yucatan peninsula, which is
equivalent to exile, 'i o put the peon in prison means
nothing to him; he has a quiet time, his friends bring
him food, he is required to clean the streets or do
similar municipal work; it is no punishment to him;
but to be placed in the army means wailing and the
gnashing of teeth among his friends.
(ri)af Ur 16
PACHUCA — AN OLD MINING CENTRE — ANCIENT
METHODS — THE DISCOVERY OF THE PATIO
PROCESS — REVOLUTIONARY DAYS — THE INVA-
SION OF THE MODERNS.
ACHUCA is approached from
V? Mexico City over a railroad that
traverses the wide volcanic
plains covered with vast planta-
tions of maguey, in serried lines
stretching out like an army in
skirmishing order. A journey
3 of 62 miles brings the traveler to
he foot of brown hilis that rise to
above the valley, v •'•'i is 8,200
• cn-level. The morning I ~...v. em first,
st.ii liid their summits .''id ?'!> them the
1 rr'a*;' J, is like far-
a whitt u
a range i
feet abo- :
the mists
possibility of a greater height,
away Kalgoorlie in the matter of dust ; it swirls round
every street corner and smothers the picturesque in
the dry folds of the commonplace. In the plaza,
among the graceful pepper trees, there are two speci-
mens of eucalyptus, fifteen to twenty years old, whose
dark blue foliage and ragged columns told of a land
unknown to the civilized world for 250 years after
the Spaniard invaded Mexico. The antiseptic odor
no
AMONG THE MINES OF MEXICO
I I
J I
\h
i
H :
■1 ! I
* i
1M.:I
f
of these gum trees recalled to me many a glorious day
spent in the Australian Alps."
The pepper trees that ornament Pachuca also
came from a far country; they are called the Peruvian
tree, having been introduced by one of the last of the
Spanish viceroys, who brought them from Peru,
where he had previously held office. The eucalyptus
was introduced thirty years ago by the minister de
fomento, but it has not done very well, the soil being
too dry.
In every respect, save its dust, Pachuca differs
from any modern mining town in English-speaking
countries. The corrugated shanties and the white tents
of ephemeral mining camps are here replaced by a
solidity of construction that bespeaks a hereditary oc-
cupation. Massive stone buildings overlook the nar-
row cobble-paved streets and some of them have
architectural pretensions, as for example the offices
of the Real del Monte Mining Company, an enter-
prise of historic continuity and associated with names
famous in mining, for John Taylor & Sons were en-
gineers of the old company sixty years ago. Even
to this day John Taylor's name is honored, and in the
Santa Brigida mine there is a level that continues to
be called the canon dc Taylor. Another reminder of
the Cornish invasion is seen in the fine stone man-
sion, half smothered in beautiful bougainvillea, of
" For even in Austr.ilia there is mountaineering and snow. Go to
Bright and Harrietville in Victoria during August and climb Feather Top
or Mt. Bogong. Experto credite.
u.
o
f
\^
I I
I
l^ni
m
IH
4lr. f
ANCIENT METHODS OF SMELTING
III
Mr. Francis Rule, whom his countrymen called Capt.
Frank Rule, and the Mexican?, Don Pancho, an
honored and successful mining engineer.
Pachuca has a population of 40,000, and of this
number 7,000 work underground. The district pro-
duces 6,000,000 ounces of silver per annum and 30,000
ounces of gokl representing 9,000.000 pesos or
$4,500,000.
Most of the lodes that are productive today were
discovered by the conqutstadorcs and their immediate
(Spanish) successors, aided, to .some extent, by the
natives (Aztecs). The Spanish pioneers sought for
gold placers and extracted the metal— not much —
tiiat they found, by washing, supplemented sometimes
by amalgamation. What silver ore they encoun-
tered, they smelted with carbonate of soda (the
tcqucsquitc of the Spaniard and the earlier tequixquitl
of the Aztec), a supply of which came from the la-
goons in the valley — for instance, in the lake of
Tezcoco. Their fuel was charcoal made from fir and
oak; poisibly also thoy used some lead oie to collect
the silver in their rudimentary smelting operation.
When llartholome de Medina invented the Patio
process at the Hacienda Purisima Grande he revolu-
tionized the silver mining industry. This was in 1557;
up to that time o.ily the richest mineral could be
smelted and there was no process for treating the low-
grade ore. Medina was the first to apply amalgama-
tion to silver, despite its much earlier application in
gold mining. This was a basic improvement, but he
^1
I iJ
112
AMONG THE MINES OF MEXICO
also elaborated the f ''^r treating silver sul-
phides by chloridizi t in the presence of
copper sulphate, usiw^ .o mix the charge. This
is the Patio process, so caned because it takes place in
an inner court or yard (the patio) and from Medina's
day to this, for 350 years, it has been the characteristic
feature of Mexican metallurgy.
In 1739 Pedro Jose Romero de Terreros, who had
made money by mining in Queretaro, visited Pachuca
and became impressed with the Real del Monte dis-
trict. He spent his capital, said to have been $60,000,
and borrowed more to carry out his explorations, but
finally he struck a bonan2a and won a big fortune.
He gave the king of Spain a battlesliip and other large
gifts; in consequence, he was ennobled. As Count of
Regla he became the founder of a family of successful
miners. The}' worked the mines until 1819, when the
disorderly condition of the country, due to the revo-
lution against the Spanish Government, caused opera-
tions to cease. A few years later the mines were sold
to an English company, which look charge in 1824.
The doings of that company are still mentioned in
every Mexican guide-book, the writers of which dwell
with gusto on their wild speculation in London and
their reckless extravagance in Mexico. The £100
shares rose to £16,000 apiece, almost before a start
had been made; enormous sums were spent at the
mines, no less than 1,500 tons of machinery being
hauled across the country from Vera Cruz. In 1848
the company went into liquidation, after extracting
THE DAYS OF THE REVOLUTION
"3
$16,000,000 in silver and spending $20,000,000. In
1850 a Mexican company was organized, and it is this
o ' rsliip that survives without important cliange to
the present day." The first manager of the Mexican
company was the Inst manager of its English prede-
cessor; that was John Buchan, obviously a Scotch-
man; and despite the change of ownership there v^as
a continuity of management, the Spanish and the
British members of the staff co-operating loyally.
During the Maximilian days and the later successtve
fights for the presidency, the mines at Pachuca si^-
fered from the depredations of the military, partly
soldiers but mostly bandits. Stories are told of the
miners having to live underground for days at a
time and of the money hat was buried in the U-vels
when people at surface were bemg robbed without
compunction. Up to 1890 it was necessary to carry
a revolvc-r in the streets of Pachuc?, even in the day-
time. The Real del Monte office, for example, is a
massive .stone structure which originally did duty as
a fortress; the rotmd towers, slotted fot rifle-fire
against attacking forces, still stand a ■ each of the four
lorners of the buiMing. Every mine even today is
enclosed by massive walls, which at one time served
as protection from assault, although nowadays they
;ire retained for a different reason. They safeguard
t!ie dumps, which are recognized as having a possible
"Since thi- ua^ written the Real del .Monte mines have been sold to
a Button corporation The Anglo-Celtic invasion has begun!
I
.1 .l!
I,]
1^1
f it
114
AMONG THE MINES OF MEXICO
f 111
value in the future, for the pcones are born thieves and
their pilfering is a constant nuisance to the mining
companies. For this reason also the reduction works,
or haciendas, are enclosed within lofty walls, which are
entered by arched doorways, guarded by a watchman.
At noon the women crowd at these entrance gates
with baskets containing the dinner of their men, who
meet them there; they often squat down beside the
wall to have a chat and share a smoke, until the
lengthening shadow marks the time to resume labor.
All the peon employees of the mines and mills are
rigorously searched by the velador as they pass out
through the gate of the enclosure. The ordinary peon
laborers are cheap enough, but it is what they steal
that makes them costly. They are inveterate thieves.
All sorts of precautions are taken. At the Hacienda
Loreto, the manager proposes to make his men pass
through a water-tank and compel them to shout "Viva
Mexico" three times in order to detect any amalgam
that they may have in their mouths. And they have
other schemes for overcoming their excessive poverty
otherwise than by earning scanty wages. For in-
stance, there is a great deal of mutilated coinage and
also of counterfeits. When pay-day arrives, the work-
man, in sweeping his silver across the office-counter,
will try to palm off a spurious coin by claiming that
the cashier gave it to him. The trick is detected by
the warmth of the coin, which the man has held in
his hand just before passing it in. Punishment for
^.M
A MACHINE-MADE TORTILLA
"5
this trick is severe, as it is an offence against the Fed-
eral Government; culprits are apt to get a sentence
of several years in jail.
At Pachuca the application of mechan'^-l inven-
tion to a basic industry is amusingly illustrated by the
fact that even tortillas — the common pancake of the
country—are made by machinery. The people of
Pachuca patronize the establishment where this is
done because the cost of the machine-made tortilla is
one half that of the hand-made article and it is equally
palatable. The excellence of the local tortilla may ex-
plain the vigor of the native miner; for the barateros of
Pachuca are recognized to be the best miners in
Mexico; they have learned from the Cornish, who
settled in the district more than fifty years ago and
intermarried with the natives. The Guanajuatenses,
or men from Gunanajuato, have the reputation of be-
ing quarrelsome and less efficient as miners— which
may be for lack of admixture .uh a strain of Cousin
Jack, but we do not n • the suggestion with any
confidence.
The natives of this district, like most Mexicans,
are wonderfully clever in estimating the silver con-
tent of an ore with which they are familiar; stolen
ore is invariably bought by valuation at sight. Even
the tributers (those that work on tribute or partido)
sell the product of their work to the proprietary com-
pany on the basis of an estimate of its assay-value
made at sight by an official termed the rescatador; if
l/<
ii6
AMONG THE MINES OF MEXICO
the appraisal is not satisfactory, they can sell their ore
elsewhere. Tributers get an eighth of the stuff they
mine — that is, one sack in every eight — the remain-
der going to the company. This is the system at the
Real del Monte mines; other companies work chiefly
on contract.
A.
(Tl^apUr \7
REAL DEL MONTE — OLD MACHINERY — THE
VISCAINA LODE— ITS EARLY ROMANCE — LA
DIFFICULTAD — AN ELECTRICAL PUMP — LODE
STRUCTURE — LOCAL GEOLOGY — SCENERY.
E, that is Robert M. Raymond
of El Oro and the writer, made
an interesting visit from
Pachuca to the neighboring
mining town of Real del Monte;
this courtesy, and much infor-
mation, we owed to Sefior Don
Carlos de Landero, the man-
aging director and one of the most accomplished of
Mexican mining engineers. In a large carriage
drawn by four mules, with a driver and footman
dressed in the picturesque uniform of the company,
to the crackling of the whip and the heavy rumbling
of the wagon over the cobblestones of Pachuca, we
started on the morning of October 30, before the
misis had uncovered the crests of the range where
lies the treasure unexhausted despite the mining of
three and a half centuries. Emerging from the nar-
row streets, the road cuts the edge of the valley and
winds slowly among the brown hills, dotted with wild
maguey. At the San Francisco shaft of the Santa
Certrudis company we saw a large pumping engine
Ii8
AMONG THE MIXES OF MEXICO
I 1?!.
I w
of the Cornish ;ype, built by Bickle & Co., of
Plymouth, in 1S98. The cylinder is upright and 90
inches in diameter; the stroke is 9 feet and the pump-
column 18 inches. The capacity is S'/t cubic metres
or 1,000 gallons per minute, from a depth of 400
metres. This pump was chosen by Capt. Frank Rule,
under a former administration; it was obtained at an
enormous cost, on account of the difficulties of trans-
port and erection. Although made in 1898, it was
not at work until 1902. But once erected, the pump
has proved most efficient. The boilers are single-
flue, with two fire-places and nine Galloway tubes, so
as to be well adapted to the use of mine-water.
The distance from Pachuca to Real del Monte is
six to eight miles, by the various roads. Haulage of
ore costs three pesos per ton, the road crossing the
summit of the range, 1,100 feet above Pachuca. Only
one trip per day is made.
Nearing the divide, the road crosses the red out-
crop of the Vizcaina lode, famous in local mining
annals as that which gave such wealth to the first
Count of Regla. The story is worthy of repetition,
although it has several versions, the most reasonable
of which is here offered. In 1739, Pedro Terreros,
who is said to have made $60,000 in the mines of
Queretaro, happened to visit Pachuca. He was an
experienced miner. Becoming interested, he aban-
doned the journey to Spain, and started mining at
Real del Monte. Humboldt speaks of "the vein of
la Biscaina or Real del Monte;" it is now spelt \''iz-
3
Ji
f^ mt
H
MICROCOPY RESOIUTION TEST CHART
ANSI and ISO lESI CHART No 2
1.0
I.I
;-iM Ilia
It u^
t li£ lii 2:0
1.8
1.25 II 1.4
1.6
_^ APPLIED IM/IGE Jnc
^^ 'tib; tail Uj,r. r-l'tft
T' ^
i I
C
'^'Iv.:
P\m
: I
!!!
'}
3 i
THE VISCAINA VEIN
119
caina (pronunciation remaining unaltered, but the
Mexican orthography being substituted) and it is
evident that the name was given after Terreros came
there, for it refers to the country of his nativity,
Biscay. Most sea-goers know the Bay of Biscay.
Terreros was successful, but the increased flow of
water compelled him to abandon the main Santa
Brigida workings when they were 120 metres deep.
In the early part of the eighteenth century the water
in mines was hoisted by methods that still survive,
namely, hide bags and a windlass. Even in Hum-
boldt's day, sixty years later, much the same practice
obtained. He says: "A bag full of water suspended
to the drum of a barritel with eight horses {malacate
doble or double horse-whims) weighs 1,250 pounds;
it is made of two hides sewn together. The malacate
doble has four arms, the extremity of each arm has a
shaft {timon) to w1 ch two horses are yoked. The
diameter of the circle traveled by the horses is
seventeen varas and a half (that is, 47^/^ ft.); the
diameter of the drum is twelve (32 ft.). The horses
are changed every four hours."
However, the influx of water was finally over-
come in miner-like fashion by driving a drainage adit
(jof(2^o«) into the hillside. Humboldt says: "Avery
enterprising individual, Don Joseph Alexander
Bustamente, was courageous enough to undertake a
level near Moran ; but he died before completing this
great work, which is 2,352 metres in length from its
mouth to the point where it crosses the Biscaina
'■^^^M'^.
lao
AMONG THE MINES OF MEXICO
1.
^\k^. .'i
*■ '^HH
', %
t
1 1
vein. * * * The level was only finished in 1762
by Don Pedro Terreros, the partner of Bustamente.
♦ * * The level of Moran traverses the Biscaina
vein in the pit of San Ramon at a depth of 210
metres." But these worthy miners were plain
'Jose' and 'Pedro' until long afterward, when their
wealth and public spirit led to their ennoblement.
This adit of over a mile long was started in 1850 and
was finished in twelve years ; the smaller veins inter-
sected during the progress of the work furnished
funds for the continuation of the adit, but before it
was completed the projectors of the enterprise were —
as is usual in mining romance — down to their last
penny. When the vein was cut below the Santa
Brigida shaft, the adit was in bonanza. This was at
210 metres below surface. The orebody was worked
for twelve years and the money secured by Terreros
enabled him not only to equip the old mine but to buy
large plantations in the vicinity. He became enor-
mously wealthy; "this muleteer and illiterate shop-
keeper," so says the chronicle, became Count of
Regla. When his children were baptized the proces-
sion walked on bars of silver. Furthermore, he
loaned money to his sovereign — this was one of the
privileges of rich men in those days ; nowadays they
buy yachts and found trust companies. Humboldt
says that Terreros "known by the title of Count of
Rc'a, as one of the richest men of his age, had in
1774 already drawn a net profit of more than 25 mil-
lions of livres turnois ($5,208,750) from the Biscaina
'-\
DE-FORESTATION
121
mine. Besides the two ships of war that he presented
to King Charles the Third, one of them of 120 guns,
he lent five millions of francs ($1,041,750) to the
court of Madrid, which has never yet been repaid
him."
Near the summit of the ridge, at Hiloche, where
the Pachuca road descends to Real del Monte, there
is a fine grove of primeval oak, suggesting the forests
that covered the plains and hills of Mexico before
the Spanish conquest. A good purpose is shown in
the young plantation of cedar and eucalyptus that has
been started in this locality. Mexico has suffered
enormously from de-forestation, and the laying out
of trees ought to be one of the first duties of the Fed-
eral State authorities, as well as of public-spirited
citizens. At Hiloche is the big pavilion built in 1901
for the entertainment of 600 people, constituting a
party of the American Institute of Mining Engineers.
That occasion is remembered by a great many who
are now scattered over the mineral regions of North
America. The pavilion has not been demolished; it
is used for picnics.
Descending by a winding wagon-road we soon
reached La Difficultad, at an altitude of 2,793.27
metres. This mine is one of the chief openings of
the Real del Monte company. It affords, among
other things, an interesting example of pumping
practice. In the shaft-house there is an enormous
engine of the marine type built by Richard Hart-
mann, of Chemnitz (Austria) in 1889. This operates
Jii k f!
laa
AMONG THE MINES OF MEXICO
two stationary Rittinger pumps, with a discharge of
890 milHmetres and a stroke of 2.5 metres; also a
sinking pump of the same kind with 850-mm.
discharge and 3-m. stroke. The capstan engine,
for handling heavy piei s of pump and facilitating
repairs, is from Tangye Bros., of Birmingham (Eng-
land). These pumps have been replaced recently by
a new Swiss pump, but they are kept ready in case
of need. The Swiss pump comes from Sulzer Bros.,
at Winterthur; it has a capacity of 8,400 litres per
minute to a heigh of 240 metres, delivering the water
from the bottom, at 540 1 1., to a drainage level at
300 m. below surface. The pump was installed on
July 23, 1905; it has four compartments, alongside,
the water being forced from one into the next, each
pump re-enfo :ing the other. It is operated by a
650-h.p. motor working with 380 h.p. and was taking
about 4,000 litres at the time of our visit. The motor
of this rotary pump was supplied by Brown Boveri
& Co., of Baden, and is of the three-phase induction
type. It is constructed to yield 650 h.p. at 60 cycles
or 900 rev. per min., using 160 amperes at 1,100 volts.
The pump-shaft is coupled direct to the motor-shaft.
The motor was running at only two-thirds its normal
speed, yet it was heating rather badly; this is charac-
teristic of most Swiss motors. Although Swiss and
German motors are cheaper, they have got no
stamina and will not stand an overload like the Ameri-
can-made machines, some of which are actually guar-
anteed to carry an overload of 25 per cent for two
itii i
s
<
<
a
O
z
<
' i i V.
t ' .
1 ' ■.< '
I
1
!tr
^ 9C
O i
— -r.
U 3
5
.h ii
in r*
in
1 *i
T
A BIG PUMP
"3
hours or even longer. No suction is used, the pump
draws from a dam that affords a 50-ft. head. The
pressure in the column is 25 kilograms per centimetre.
The sump under the rotary pump is three metres
deep, the water from it being raised to the dam by a
Knowles pump geared to a motor, which gets its im-
pulse from a Koerting elevator, operated by a stream
of water descending from the 300-m. level. These
Swiss centrifugal pumps are used in other mines at
Pachuca and they are said to be highly satisfactory;
they have a particular and effective arrangement of
the runners; the makers of them are willing to guar-
antee a specific efficiency, which, as yet, American
manufacturers will not do. Four of these Sulzer
pumps (each of 1,500-gal. capacity) have been or-
dered for the El Oro mill, to raise the return water
and solution from below the zinc-room. At the pump-
station there was the usual shrine with lighted candle
on each side, and ornamented with artificial white
flowers. Here we had a timely luncheon and a pleas-
ant talk with the engineers of the mine.
The first 50 ft. of the shaft is lined with masonry
• orted by arches sprung from the country rock.
i!? shaft is not continuous; from the 440-m. level
there is a counter-shaft to the bottom. This is de-
scended on a cage with steel-rope guides. At the
440-m. level there are some large underhand stopes;
when the flat cable is worn out, its separate strands
are used for hoisting ore underground, in hides that
hold 25 kilograms apiece. These are not made in the
1 1
I,
Il
124
AMONG THE MINES OF MEXICO
shape of buckets, but they are laid flat, the broken ore
is put on them and then they are laced so as to make
a parcel. The ore hoisted by windlass in this way is
discharged into side-dumping cars, which are run
on a wooden track lined wiih an iron band to the sta-
tion at the shaft, where the ore is dumped onto a plat-
form to be shoveled into a skip. Altogether, it affords
a curious mixture of old and new methods; it is a
hybrid practice. At the 463-m station we changed
from the counter-shaft to the main shaft, and while
waiting for the cage we watched some men who were
loading the accumulated waste into ox-hides; these
held 300 kilograms or the third of a ton, and after
being laced they were hung by chain to the bottom
of the cage, the material being used at the next level
for filling. All the rock broken in shaft-sinking is
raised in this way. and even water, just as they did
in the days of Pedro Terreros. As the five men filled
and then laced the rawhide, they put it aside lor the
next trip of the cage; when I first saW it, I thought it
was the carcass of a dead mule, and it smelt like one.
In walking llirough the workings, one notices
that the cross-cuts are walled up, the walls being
often sealed with clay to divert the ventilation. There
is a good deal of masonry in the mine, and different
parts of it are shut off by iron gates, so as to prevent
pilfering. There is no timbering worth mention.
The ore is mainly quartz; it is often ribboned by the
banding of rhodonite and sulphides (iron pyrite and
argentite) ; in many respects it reminded me of the
-PI* w
THE SANTA INEZ VEIN
las
veins in the Alice and Lexington mines, at Butte.
Montana. The accompanying sketch (Fif;. 17) of the
Santa Inez vein is i fair example of the lodes in the
Difficultad mine. Both walls are well defined; on the
fool (G) there is a wet slip; £ is a band of rhodonite;
L) is mainly amethystine quartz; F and B B are sul-
phide streaks; J B is massive poor quartz; B to C is
mottled by brecciation; between D and E there are
Fic. 17.
Streaks and spots of sulphides, including argentite, a
little galena, and occasional yellow zinc-blende; E F
is brecciated andesite, now partially silicified; F G is
crushed quartz. The whole widtl of lode is seven to
eight feet. At the Difficultad mine, the low-grade
ore left on the dump is said to contain 400 grams >f
silver and 2 grams of gold. This aflfords an idea of
the cost of working. At the Barron mine, the ore
1 ^i:!
I
"ill
'::t
if i'
I' I
1 'i li
136
AMONG THE MIXES OF MEXICO
is said to average 800 gm. silver and 4 gm. gold, while
in the Difficultad it is said tc» carry, for an average of
eight metres, not less than 1 kilogram of silver and
the usual proportion of gold.
It may be added that the prevailing formation
about Pachuca is andesite ; the veins arc lines of frac-
ture which have been healed by silicification. There
exist in the district several islands or caps of basalt
connected with vents and there are dikes of rhyolite
accompanied by slight mineralization along their
walls. For details of the geology, the reader is re-
ferred to a valuable paper by Senor Ezequiel
Ordonez."
On leaving Real del Monte by the southern road
a good view of the surrounding country is obtained
by looking back. To the left is a rounded ridge
clothed with groves of oak; to the right, a conical
hill surmounted by a coppice of dark oak and cedars
of Lebanon, and under their ohade the white-walled
English cemetery where many a Cornishman has
gone underground for the last time. Between these
flanking hillslopes, framing a picture, there are the
white houses and red roofs of the town, surmounted
by Moorish church-towers, among which, curiously
out of place, is the Cornish engine-house with its lofty
chimney rising above the castellated enclosure of ti.e
Difificultad mine. Behind the town are green hill-
sides, and further back, after the interval that marks
"'The Alining District of Pachuca, Mexico,' Transactions American
Institute of Mining Engineers, Vol. XXXII, pp. 224-241.
■In
A WIDE PROSPECT
IJ7
a deep barranca or gorge, there stands, outlined
against the hlue sky, the mountain crowned by the
battlemcuted rocks of Zumate.
After crossing the summit and beginning the
long descent to Pachuca, there is much to be seen that
typifies the Mexico of today. The liroaf nd winding
road cuts through gray-purple andesi ■ it is lined
with massive stone culverts and doet redit to the
engineers responsible for the construrtion. ft skirts
brown hillsides, darkened in spots by the wild maguey,
with the tall central stem that is the sign of an uncul-
tivated condition, i ;ere is an occasional cactus and
a few palms, mainly the izote from the fibre of which
are made the straw hats of the peones. Whitewashed
monuments dot the surface and, in their occasional
sequence of direction, mark the boundaries of mining
property. Yellow scrub fringes the road and en-
hances the value of the purple in the distance. A
flock of sheep, a string of patient donkeys laden with
charcoal from the forests, other burros coming irom
the valley and laden with pigskin bags inflat' 1 with
their burden of pulque; some saa-faced Indian men
trudging up hill, one of them with a baby slun^ . i her
rcboso, another walking patiently v.'hilr her man rides
alongside on his mule; then a cava!^'"r with wide
sombrero and gaily caparison^ ' idille, a .irrape thrown
over the silver-mounted pumiii.i and riding his horse
superbly; a wagon heavily laden with sacks of ore, its
brakes crunching noisily, drawn by ten mules, with
silver bells, and driven by a brigand-like muleteer; all
138
AMONG THE MINES OF MEXICO
these are part of the stream of Hfe that we pass or
meet on this road. But the foreground is not all the
picture; at our feet, to the south and west, lies out-
spread the vast plain known as the valley of Mexico,
crossed by white streaks of dusty road, checkered by
squares of cultivation, the yellow patches of maizf?,
the green of barley, and the occasional darker shade
of alfalfa, with other rectangular lines tl t mark the
serried rows of macjuey?'' Sunlight and shadow shift
over Ibe vast expanse; in the distance, more than
16,000 feet high, rises the snowy crest of Ixtaccihuatl
— 'the white woman' — partially veiled in a cloud, and
by the Aztec name recalling the pathetic fate of an
ancient race. In middle distance there is a blue ridge
behind which is jNIexico City, and to the right, under
the mountain of San Cristobal, hides the dusty town
of Pachuca; in front are several famous mines —
Cortcza, El Lobo, Santa Gertrudis, Barron, and La
Blanca — each in its walled enclosure and dominated
by a towering shaft-house of stone. And then, before
we realize it, we are awakening the echoes of the nar-
row streets of Pachuca, and amid the cracking of our
cochcro's whip and the warning shouts of those that
clear the way, we pull up at the railway station, just
in time to catch the train.
"There is no maguey on the west coast of Mexico: only one-tenth of
the population of the entire country drinks pulque, chiefly in Mexico City
and its vicinitv, including such mining towns as Pachuca and El Ore. It
if unwholesome because it is drunk when still in process of fermentation;
if the people d d not take this stimulant they would take some other.
|;?
Cbap Ur IS
THE REDUCTION WORKS OF PACHUCA — THE
HACIENDA DE GUADALUPE — TREATMENT ON THE
PATIO — A METALLURGICAL SURVIVAL — SOME
CRITICISMS.
ACHUCA is proud of its hacier.
das de beneficio or reduction
works, of which there are seven
large ones. Six of these are in
operation and they treat 5,000
tons per week. Three of them
are custom works; those of
Guadalupe, La Luz, and Loreto
are not. At the entrance of the haciendas, and even of
private residences, one sees the big iron hoods of the
mercury retorts. They are buried in the ground, one
on each side of the gateway and, being 5 to 5^ feet
long, they have the appearance of spikea guns.
The Hacienda de Guadalupe treats 900 tons per
week, this being the output of the Santa Gertrudis
and Guadalupe mines. At the mine the ore is broken
by hand, and picked over; the 'best selected' assays
"ver 10 kilograms of silver per metric ton and is sent
to K .rope, the second class, carrying less than 10 kilo-
grams, but over 2 kg. per ton, is shipped to the smelter
at Monterrey, while the mine-run, containing less than
2 kg., comes to the hacienda. Here it is screened to ^
I
!)
I;
I , I !l
'ty
I I
li
130
AMONG THE MINES OF MEXICO
inch, the oversize passing through Cornish rolls, while
the undersize is shoveled into bins. These are built
of stone; they are brick-lined at the opening, whence
the ore falls into cars that take it to Chilean mills.
The oversize, after passing through the rolls, goes
through a trommel (2 ft. diam. and 3 ft. long) with
half-inch openings, the oversize going back to the
rolls while the undersize falls to the ground, to be
shoveled into cars, in which it is taken to bins above
the Chilean mills and subsequently fed into them by
shovel. There are 14 Chilean mills; the die-rings (5
ft. inner diam., 6 ft. outer) and shells are composed
of Siemens & Martin steel, made in Germany. The die
lasts one year, the shells twice as long. There is an
iron ring inside the steel shell. Each mill (inside
diam. 1.85 m.) has six openings, guarded by a 60-
mesh screen, all on one side. The discharge passes
into a vat, whence it is raised by a centrifugal pump
to distributors above the 14 concentrators. These are
vanners — with belt 1.8 metres wide — known as the
Johnston table and manufactured by the Risdon Iron
Works, San Francisco. It does good work, the belt
being heavy, so as to give it the motion of a batea
instead of being simply supported on a frame. The
concentrate is shipped to Europe; it contains 14 to
15 kg. silver and 100 gm. gold per ton. The yield
(from 900 tons of crude ore) is 21 tons per week, of
which 13>4 tons come from the vanners and 7^ h
from canvas tables that receive the tailing from the
vanners.
k
THE HACIENDA DE GUADALUPE
131
The tailing that results from this concentratiori
process goes to vats or bins; these are structures built
of masonry, 4 to 5>^ meties deep. Here the pulp
settles and the water is drawn off to a well, from
which it is pumped for use in the mill. Stated briefly,
the process of ore reduction consists in grinding fine
with Chilean mills, extracting the heavy sulphides
(with their associated gold) on concentrators, and
then treating the tailing (containing the bulk of the
silver) by amalgamation on the patio.
On the flat ground below the terraced slope form-
ing the site of the mill just described, there stretches
the broad expanse of the patio, where the process of
that name is carried out. Patio means a yard or enclo-
sure, and the process derives its name therefrom. The
patio of the Hacienda de Guadalupe is the size of a city
square, it is paved with stone and divided into rect-
angular spaces, 30 by 25 metres, in which twenty sep-
arate charges or tortas, each weighing 300 tons, are
undergoing various stages of treatment. Each bin
or vat that holds the pulp or tailing from the concen-
trators, has a vertical opening 5>4 feet wide which is
kept closed by a series of boards (6 to 9 in.). These
are removed one by one so as to allow the sludge to
flow along the canals— 3 ft. high, 6 ft. wide and built
of stone — that lead into the patio itself. The flow of
the sludge is assisted by a scraper (camon) pulled by a
horse. This scraper is a plain plank, two inches thick,
to which chains, connecting with the traces, are at-
tached, as shown in the photograph facing page 134.
m
y
\
\\Jih
... :|/
132
AMONG THE MINES OF MEXICO
El camonero, the horse that does this duty, must be
strong, for the work is hard; he scoops the slime
along, to the accompaniment of much splashing and
the encouraging shouts of the driver who controls the
operation. Openings, at various points along the
canal, serve to distribute the slime to separate rectan-
gular stone-paved spaces, where the chemical work is
done. Each rectangle, 25 by 30 metres, is del'mited
by two timbers (4>4 by 8 in.) placed one over the
other so as to make a partition 16 inches high. The
torta that they enclose is 30 centimetres thick.
The slime or tama is allowed to thicken, by loss of
moisture through evaporation. Then comes the ad-
dition of the first chemical, common salt, which is
thrown over the charge like a shower of hail. The
salt is obtained from the lagoons near Zacatecas and
is adde . in the proportion of 6 to 7 per cent of the
weight of the ore. This is an excess, but it is found
to accelerate action and to diminish the consumption
of mercury. After this part of the process (called
ensalmorar) is finished, the mixing or repaso begins.
This is done by the trampling of horses or mules. One
man, himself on horseback, drives 12 animals, four in
a row, tied by the neck to each other. The cracking
of the whip, the slushy tramp of the horses, and the
shouts of the driver give animation to the scene. This
goes on by day only, from 7 in the morning until 2
o'clock in the afternoon. When the day's labor is
ended, the horses are driven through a big tank to be
cleansed, when more shouting and splashing enlivens
THE PATIO PROCESS
133
the hacienda. This mixing continues for 24 to 30
days. Each afternoon every portion of the torta is
turned over with shovels in the hands of 12 to 15
men. After the first three days comes thr addition
of copper sulphate (bluestcne) followed by further,
mixing, and then the mercur;- is introduced. The
'bluestone' comes from the Unitod States; it is added
to the torta in the proportion of 0.4 to 0.6 per cent of
the weight of the ore. In looking over a patio in
which the charges are in various stages of treatment,
some just salted, others just showered with copper
sulphate, the contrast between the rectangular
patches of white and blue leaves a vi/id impression.
The mercury is added in the ratio of fully eight
times the amount of silver estimated to be in the
charge undergoing treatment. It is carried in a cloth,
folded like a ':ag, and swung freely, so that the mer-
cury squeezes through in the form of small globules.
This is done to ensure thorough assimilation; the
operation being appropriately termed incorporacion.
Five or six men perform this work, on the fourth day.
At the end of the process (after 24 to 30 days, as de-
termined by test) more mercury is added, in the pro-
portion of 5 kilograms of mercury for each kilogram
of silver present in the charge, makinf' about 2,500
kg. to each torta, this being introduced for the purpose
of collecting the amalgam already formed. This
operation is termed the bafio. During the continu-
ance of the treatment the torta is tested by panning
( i
i
',• ■■ r !
ii .■■>
j.:
134
AMONG THE MINES OF MEXICO
samples in clay saucers (6 in. diam.) called jarros.
The operator pans the stuff down to a button of er-
cury and squeezes it between the thumb and index
finger, to test its consistence, a flat bit of amalgam
remaining, of a size indicating the extent to which
amalgamation has proceeded. The rejected sand
from this .anning undergoes the ordinary fire-assay;
when there is no further decrease in the content of
the tailing, complete extraction is indicated and
mixing on the patio ceases.
Then the horse with the scraper (camon) is em-
ployed to move the charge forward to a sump or
lavadero, the patio being finally swept clean by 12 to
16 peones with brooms; the mercury can be seen in
small pools and is splashed about during the manipu-
lation required for this clean-up. The charge is
moved to a basin {cajon), 8 by 10 ft., where seven
men, standing in water just ove- their knees, stamp
around, and stir the stuff, while clean water is being
added and fresh material is being fed into the cajon.
The top of this basin is level with the floor of the patio;
the bottom of it is six feet below the pavement and is
enclosed in masonry, except on the lower or outlet
side, where there is a barrier made of two boards,
which are perforated with 3-inch holes, twelve of them,
in cK:sters of six each. The amalgam and mercury col-
lect at the bottom, while the overflow drops into large
cast-iron hemispherical basins (apuros), of 2>4 ft.
diam., which serve as traps. There are five of these,
\ .
ICi- Camiinkho
MoVIM; Sl.lMK (INTO
THF Patio
■\ Tube - Mill
IN THE
Hacienda
1,\ Union
AT Pal H CCA
' t
m
v^m
. :vl'"f ^
trim \
Pi f
<;. MK.HANIC.M. ri.ii(;H. II. llnksKs MiMM;. K Mkn Siii.vki.im;
Two ViKWS OF THK P.\TIO PROCESS
■J ' i
COLLECTING THE AMALGAM
135
distributed along the exit-sluice below the sump.
From the last apuro, the pulp flows over two parallel
sluices with riffles, and in this a dozen or more boys,
8 to 9 years old, stamp around, in order to aid the
separation and arrest of any escaping amalgam.
These little fellows, chocolate colored, with big straw
hats and thin bare legs, are kept on the move, so as
to stir the slime; they wade around at the bottom
of a canal 10 to 12 feet below the lev^l of the patio.
They receive 37 centavos, or about 20 < ents, per day.
Most of the amalgam is caught in the sump and in
the first two apuros at the head of the sluices. This
clean-up occupies 16 to 17 hours. Finally, the rich
deposit at the bottom of the basin is washed, one of
the boards of the lower barrier being removed, while
fresh water is turned in. What amalgam gets out of
the ca)on, lodges in the first (and biggest) apuro. At
the very end of the operation more water is added;
the peones use scrub-brooms and sweep the bottom
clean. The amalgam and mercury make a big show-
ing; they are lifted in iron ladles; these are made from
the flasks in which the quicksilver is bought, their
tops being cut off, and an iron handle 'nserted. From
1,500 to 2,000 kilograms of amalgam are obtained
from the clean-up of a single torta.
Six hundred horses are used on the patio; they
last four or five years, if young; the older ones last
only six months. They become poisoned by the
copper sulphate; hence the washing each day. Some
%m^
1
.-a|,,
136 AMONG THE MINES OF MEXICO
of the horses are found to gather a lump of amalgam
in their stomachs, as much as half a kilogram, say,
one pound. This used to be removed when the horse
died, but now the Government claims the deceased
animal, without permitting dissection, and it goes to
the crematory. What happens to the silver amalgam
is not stated. ,., ^
The extraction is 80 to 85%, the tailmg (jales)
containing 100 to 150 gm. silver, say, 3 to 5 oz. per ton.
The gold is caught in the concentrate on the vanners;
practically none of it is saved on the patio. Never-
theless, down the creek there are two plants that
re-work the tailing from the hacienda. To anyone
accustomed to stamp-milling, it is surprising how the
mercury is splashed about. The pavement of the
patio itself must absorb some of it, for this pavement
is made of slabs, which are irregular in size, but
usually 1 by 1>^ feet, of volcanic stone, a basalt called
recinto.
In another part of the hacienda one can observe
the working of a mechanical mixing machine, de-
signed to be a . oor-saving modification of the Patio
process itself. In a rectangle, 20 metres wide and 75
meties long, a plough, with eight blades, movmg
sideways, travels up and down. It is operated
through a ratchet gear by a man who sits on the
machine, as it is pulled by an endless cable of one-half
inch diameter. This treatment requires 45 days and
gives the same extraction as the ordinary Patio
A MECHANICAL MIXER
i37
process. The superintendent prefers the old-fashioned
horse method because it requires less time. It can
be said truly that the trampling of the animals affords
a better aeration of the charj:je than the mechanical
plough, which appears to go through the sludge
rather than turn it over. There should be more
turning of the furrow.
Mechanical devices in place of animals were tried
long ago and they have been used in different parts of
Mexico, especially Sonora. In M. C. Roswag's
'Metallurgie de I'Argent,' there are descriptions of
such substitutes, which in English are called 'knead-
ing' machines and in Spanish repasadoras.
Other observations are permissible. The small
boys that tramp about in the tail-sluice give their toes
as riffles to assist the settling of escaping particle? of
amalgam. The stirring in the clean-up basin, as done
by seven grown men, has its humorous feature, but it
is effective. The method of moving slime onto the
patio by the camonero is an absurdity at first sight, but
it obviates a costly conveyor, and botn horses and
men are cheap at Pachuca. The Chilean mill affords
better grinding than the pounding action of the
stamp, although it seems strange to see the pcjncs
shoveling into the mills and then taking a rest, when
a mechanical feeder would do it so nicely. Th*; tern
porary canals made between the torta and the cajon, to
confine the passage of the pulp, are kept tight with
manure, the droppmgs of the animals on the patio,
I '
138
AMONG THE MINES OF MEXICO
thus contributing smells to the sights, a combination
not uncommon in Mexico. There is a striking con-
trast between the modern vanning tables and the
patio itself, the whole picture exhibiting a sublime
disregard of all modern mechanical ingenuity as
applied to the handling of material.
The accompanying photographs will aid the
foregoing description. J A indicate the position of
the Johnston vanners; B B are the sludge vats, with
their outlet at C C. D is the camon or scraper. E is
a canal or conduit for the slimed ore. In the three
photographs given on the page opposite, ihe first
shows the workmen mixing the charge, with the
horses at work behind them. In the second, the men
are mopping the floor of the pado and sweeping the
amalgam into the basin or cajon, shown in the bottom
illustration ; here the work of separating the amalgam
is finished and the men are cleaning up.
1 !
PBir^-'------
Three Stages ;n the Patio Process
'-^l **i. "Xt
HOKSKS TRKAliiNi, THK Ch,\Ri;E
'%
n
Ki. Camoxkko
At the Haciciula di- Guailalupc, ['acluica
chapter 19
THE CHEMISTRY OF THE PATIO PROCESS— CHEM-
ICAL EQUATIONS— OBSERVATIONS OF HUMBOLDT
—LOSS OF MERCURY— CONTRAST OF POLICY.
HE Patio process has been used
on a large scale and continu-
ously since 1557, therefore it is
probable that a great many have
attempted, at various times, to
investigate the theory of it;
nevertheless, iew have been bold
enough to publish the results of
their investigations. In oflfering a few notes, it is
vi^ith the hope, mainly, of helping the younger
students in our profession.
The right amount of bluestone'* is important, for
if it be insufficient, the copper sulphate is converted
into the sub-cxide, which reacts on the mercury so as
to sicken it, covering it with a film. The bluestone
consists of the sulphate of iron as well as . f copper,
for it is formed by the roasting of chalcopyrite; these
sulphates react on the sodium chloride so as to lib-
erate hydrochloric acid, which, according to Ortega,"
first forms cupric chloride and then, in the presence
"Magistral, an impure mixture of copper and iron sulphate, was for-
merly employed. Bluestone, commercial copper sulphate, has replaced
it in practice.
" 'The Patio Process for .\malgamation of Silver Ores,' by Manuel
Valerio Ortega. Transactions American Institute of Mining Engineers,
Vol. XXXII, pp. 279-282.
1 I
II
140
AMONG THE MINES OF MEXICO
of mercury, cuprous chloride and mercurous chloride.
The cuprous chloride absorbs oxygen and then re-
duces the silver sulphide in the ore, with the forma-
tion of mercuric sulphate and the liberation of the
silver. Thus:
2NaCl + CuSO, = Na,SO, + CuCl,
CuO, + Hg = CuQ + HgCl
CuCl + 4O + Hr- -f- Ag,S = CuCl -1- HgSO* + 2Ag.
On being liberated, the silver immediately forms an
amalgam with the excess of mercury.
On the other hand Bustamente" claims that the
iron sulphate in the magistral is essential, the role of
the copper being, in many respects, subordinate, al-
though necessary, to the iron. According to his expla-
nation, ferric chloride is formed; this, on being re-
duced to a lower chloride, releases chlorine, which,
while nascent, acts upon the silver mineral, transform-
ing it to a chloride. A subsequent reaction with the
hydrated oxides liberates the silver and hands it over
to the mercury, for amalgamation. The copper sul-
phate acts as a carrier of oxygen and the presence
of 't is required to preserve the mercury in a metallic
s. te.
The old theory, to be found in most text-books,
was that after the cupric chloride was formed, a re-
action with the silver sulphide mineral, in the pres-
ence of air, yielded cuprous chloride and argentic
"'A Study of Amalgamation Methods, etc.,' by Miguel Bustamente,
in Transactions American Institute of Mining Engineers, Vol. XXXII,
p. 489.
COMPLEX CHEMISTRY
141
chloride, the argentic chloride coming in contact with
the mercury, so as to form an amalgam, together
with mercurous chloride, thus:
(1) CuSO,+2NaCl=CuCl,+Na,SO«
(2) 2CuCls+AgjS=2AgCl+Cu,a,+S
( 3 ) 2AgjS+4Cu,Cl,+60=4AgCl+2 ( CuQ.+sCuO ) +2S
(4) 2Aga+3Hg=Hg,a,+Ag,Hg.
It is a complex bit of chemistry, rendered obscure
by the lack of accurate data. The Patio process is
rarely checked by systematic analyses and assays, so
*hat, despite the three centuries and a 'naif during
which it has been used in Mexico, there is but little
evidence available. One or two points stand out
clearly. If silver chloride be formed directly from
the action of the chlorine liberated from the salt, and
if this be a necessary chemical stage, why is it that ore
containing hornsilver or natural silver chloride cannot
be treated successfully by this method? If copper
sulphate be the sole active agent in the magistral, why
is it that the pure copper sulphate gives such poor
results? If there is no direct chlorination of the
silver, why is so much salt required? The first two
queries have been answered; the last can bo '. cplained
on the ground that the brine serves as a solvent for
the cuprous chloride, rendering it more active as a
carrier of oxygen.
Humboldt makes several interesting remarks-
concerning the process of amalgamation on the patio,
"'Political Essay on the Kingdom of New Spain.' Black's transla-
tion. Vol. Ill, Book IV, p. 268.
R ''^*
w.
:«' 'r*
142
AMONG THE MIXES OF MEXICO
as carried out during his visit to Mexico, a hundred
years ago:
"The process invented by the miner of Pachuca
is one of those chemical operations, which for cen-
turies have been practised with a certain degree of
success, notwithstanding the persons who extract
silver from minerals by means of mercury, have not
the smallest acquaintance either of the nature of the
substances employed, or the particular mode of their
action. The azogueros (or amalgamators) speak of a
mass of minerals as of an organized body, of which
they augment or diminish the natural heat. Like
physicians, who, in ages of barbarism, divided all -u'-
ments and all remedies into two classes, hot and cold,
the azogueros see nothing in minerals but substances
which must be heated by sulphates if they are too
cold, or cooled by alkalies if too warm. The custom
which was already introduced in the time of Pliny, of
rubbing metals with salt, before applying the amal-
gam of gold, has undoubtedly given rise to the use
of muriate of soda in the process of Mexican amal-
gamation. This salt, according to the accounts of
the azogueros, serves to clean and to unskin the silver,
which is enveloped with sulphur, arsenic, and anti-
mony, as with a skin {tililla or capuz), whose presence
prevents the immediate contact of the silver with the
mercury. The action of this last metal is rendered
more energetic by the sulphates with which the mass
is heated; and it is even probable that Medina only
employed simultaneously the sulphate of iron and
ii
HUMBOLDT'S DESCRIPTION
143
copper and the muriate of soda, because he discovered
in these first attempts, that salt was only favorable to
the process in the minerals which contained decom-
posed pyrites. Without having any clear idea of the
action of the sulphates on the muriate of soda, he
endeavored to recompense (refaire) the minerals, that
is, to add magistral, to those which the miner considers
as not vitriolic."
The 'hot' and 'cold' condition — called calentum,
or fever, and frio, or chill — are untechnical references
to oxidation and reduction, the sulphates contributing
oxygen as fuel to the chemical reactions, while the
alkali of the lime, ashes, or cement copper employed
to doctor a 'hot' torta, neutralizes any excess of acid
sulphate. The idea that the silver of the argentite
was coated with sulphur, which had to be removed
to permit of contact with mercury, illustrates the
ignorance of what constitutes a chemical compound.
The sodium sulphate is formed by the reaction be-
tween the "muriate of soda" or common salt and the
copper sulphate, so that the addition of it simply
anticipated a reaction consequent upon the use of
magistral. The mention of "decomposed pyrites"
suggests the agency of iron sulphate in the Patio
process, an agency the exact working of which is
yet a subject for deba^^e among metallurgists.
Further on, he explains how, by the leaden look
of the mercury, they inferred the commencement of
chemical action; when a fine gray powder was sep-
144
AMONG THE MINES OF MEXICO
arated from it so as to stick to the fingers, they said
the paste was too 'hot' and they 'cooled' it by adding
lime. If it preserved its metallic lustre, or was cov-
ered with a reddish pellicle or film, if it did not
appear to act upon the mass, the amalgamation
was considered too 'cold' and they endenvored to
'heat' it {calentar) by mixing magistral.
The "leaden look of mercury" is due to excess
of copper sulphate, with formation of flouring mer-
curic chloride, which, in the presence of sunlight and
organic matter (such as the droppings of the horses
or mules that trample the torta) is converted into
oxide; this is almost insoluble in the brine, formed
by the excess of salt, and in consequence it is apt to
be lost in the torta when it is finally discharged after
treatment. When the torta is cold, the mercury is
apt to show 'flouring'; it is in minute globules that
do not coalesce, being coated with a reddish film of
copper sub-oxide, because there is not enough of the
copper sulphate present to generate chlorine from
the salt, so as to form cuprous chloride.
At first the charge was mixed by the treading of
a number of bare-footed workmen, but in 1783 Juan
Comejo brought, from Peru, the i.ea of using mules.
The Gove'-nment granted him a privilege for it.
This decreased the expenses of the process by one-
quarter.
Then Humboldt continues: "It has been long
proposed to cover the surface on which the pastes
t A it
rJ
m
THE WASTE OF MERCURY
145
repose with plates of iron and copper instead of flags;
and it has been endeavored to stir the mass by work-
ing it with ploughs of which the share and coulter
should be made of the metals mentioned, but the
mules suffered too much from this work, the schlich
(slime) forming a thick, and by no means ductile
paste." Finally, he concludes: "The process in-
vented by Medina possesses the great advantage of
simplicity; it requires no construction of edifices, no
combustibles, no machines, and almost no impelling
force. With mercury and a few mules to move the
arrastrest we may, by means of amalgamation por
patio, extract the silver from all the meagre minerals
near the pit from which they are taken in the midst
of a desert, provided the surface be sufficiently smooth
to admit of the establishment of the tortus; but this
process has also the great disadvantage of being slow
and causing an enormous waste of mercury."
How great this waste of mercury was, it is diffi-
cult to realize today when the old tailing has been
washed by several generations of patient peones, or
else scattered abroad by the torrential rains of the
tropics and the dry wind of the high plateau. They
used eight parts of mercury to one of silver. At El
Oro the mill of 100 stamps was run for six years with-
out the purchase of a single flask of quicksilver. The
tailing heap of the old hacienda — built 30 years ago —
gave all the mercury wanted. In cyaniding the tail-
ing, the mercury was dissolved, to be precipitated in
I' ■ I .r' •
I -rr
^ifiU
i I
' 4 I i
146
AMONG THE MINES OF MEXICO
the zinc-boxes with the gold. The precipitate was
retorted in order to drive off the water and the quick-
silver. Out of a retort of 1,000 pounds there would
be obtained 150 pounds, or two flasks, of quicksilver.
Another suggestive incident may be mentioned.
Nearly two years ago, when the mechanical ploughs
(repasadoras) were installed at the Loreto mill, a
cement floor was laid down, and in excavating for this
purpose a big find of quicksilver was made, the earth
being saturated with it. It is said that mercury
worth more than 30,000 pesos was obtained.
As Humboldt said, the Patio was successful de-
spite the ignorance of any chemical reactions in-
volved. It is only recently, when the process is being
discarded for more effective methods, that the chem-
istry of it has been investigated intelligently. As used
for 350 years it was an empirical process, regulated
by the experience obtained with the particular rre of
each district.
The Patio process was invented when men,
horses, and time - ere cheap, when there was no haste
to realize on the ore in the mine. And this spirit
survives; when I asked one of the Mexican engineers
why they did not exploit a certain rich mine on a
larger scale, he said that the shareholders did not
care to rush the production because they feared the
mine might be worked out toe soon. This is the
European idea of fifty years ago; the opposite of it is
the American notion that it is best to gut a mine
i . • i! w
if . T'lF
■!. ;lr ail
<
<
i
n \
I
t 1 '.{
i
ai (
■i!
I
iui
DIFFERENCE OF IDEAS
147
evpeditiousiy and make the maximum money in the
minimum time. Both extremes are extravagant.
Pachuca affords examples of other methods be-
sides the ancient Patio process. Some of these I r.hall
describe in the next chapter.
'
^.."^Jj>'^4fcS:"Ji^';?•iJI^
/'
chapter 20
I A^-
' ih,
r i
riin
OTHER METALLURGICAL PROCESSES - THE
H\C1ENDA LA UNION -KROEN'CKE'S METHOD -
TLMJE-MILLS-THE BARREL PROCESS-FRANCKE'S
PROCESS -CHILEAN MILLS -RETORTING THE
AMALGAM — THE PLANILLA.
T the Hacienda La Union there
is much that is interesting to the
metallurgist. The process is
that of Kroencke, used in Chile,
but modified by the manager,
Francisco Narvaez, formerly a
captain of artillery and graduate
of the military engineering
school of Chapultepec. As a military officer he
visited the United States three years ago, and, be-
coming much interested in niclu'Uir^ncal pr;;ct?ce, he
resigned from the service to undertake the work for
which he has since shown so much aptitude.
The scheme of milling involves first a Sturtevant
roll-crusher, which reduces the ore irom 3 or 4 inches
to ^-inch diameter. An Imperial shaking-screen
sizes the material to 16 mesh; the undersize is fed
into an Abbe tube-mill ol 5-foot diameter and 22 feet
long, while the oversize passes through rolls without
springs, with 14 by 27 inch faces (made by the Denver
Engineering Works). The amount of iron that gets
THE CHILEAN MILL
149
into the pulp is only 2 per cent ; this fact is important
in view of the chemical treatment that follows. Capt.
Narvaez was led to adopt this method by reading
the book on 'Ore Dressing,' by Robert H. Richards.
Later on, without stopping the regular operation
of the mill, he intends to replace the barrel-amalgama-
tion process by cyanidation; as far as grinding is con-
cerned, his results indicate that Chilean mills will
more than hold their own against the competition of
newer devices for pulverization. They permit of a
very fine grinding at a low cost per ton. 7rom an
average of thirty sizing tests, made on the product of
the Chilean mill at this hacienda, Capt. Narvaez ob-
tained the following results:
Assay in Percentage
silver, of assay-value
Percentage. Grams. retained.
riner than 200 mesh 80.00 1.290 93.65
Between 200 and ISO mesh 4.75 626 269
ISO ■ 100 •• 13.45 385 0.47
100 " 80 " 1.50 355 0.48
80 " 60 " 0.41 346 0.01
Tiie original a?say v">f the ore gave 1,102 grams per
metric ton. One of these mills, for example, worked
from February to June without stopping once for re-
pairs; and with the ordinary unskilled labor, it ground
15 to 18 tons per 24 hours from 1^-inch size to the
fineness recorded in the tests just quoted. The cost
per ton did not exceed one peso, or less than 50 cents
per ton.
At the time of my visit there was one Krupp
tube-mill, with other foundations ready for the Abbe
I
150 AMONG THE MINES OF MEXICO
tube. The Krupp tube crushed 50 tons to 100 mesh
in 24 hours. It was preceded by a Krupp ball-mill,
which reduced the ore from 1 /2-inch size to 24 mesh.
It is necessary to grind dry, on account of the barrel
process, which constitutes the main feature of the
treatment. With the use of Chilean mills, as at the
time of my visit, it was necessary to dry the product.
Both ball-mill and tube work dry. Silex linmgs m
the tube last three years. The use of the Chilean mills
yields iron that becomes oxidized by the water, while
the iron worn away from the balls in dry crushing
through the Krupp mill, is in a metallic condition and
in an amount suited to the later chemical reactions in
the barrel. The ball-mill is charged with four balls
of eight kilograms each per day, this representing the
iron abraded from the balls themselves and the lining
also. For setting the silex lining in the tube, a com-
mon cement with two parts of sand is used; it sets in
three davs. Trouble has been made by the fact that
some of the sectional pieces of lining are not cut to the
right curve; however, only three dropped out after
being in use for a month. The flint pebbles are
bought from Indians, who will not divulge the lo-
cality where they find them. They are paid 35 pesos
per ton, while the imported pebbles cost 75 to 90
pesos per ton. The tube has no screen, the material
passes through the length of it and is then discharged.
In the new plant as it will be re-arranged, the
Krupp ball-mill will deliver its product to the Abbe
tube, for re-grinding, and both will work wet, instead
7T* 7
%JR
BALL-MILLS AND TUBE-MILLS
151
of dry. The ore that goes to the Chilean mills will
be crushed to 1 V: 'nrh. size in a breaker and from the
Chilean mac' les tht pnif will be pumped direct to
the vats and c/rriidec]. ]•" om the day (in January,
1906) that E M. HaiT'iltf n, associated with Charles
Butters, made a c;<»:-Me test on the ore at this
hacienda, Csipi. Narvaezhas made more than 200 tests,
obtaining an extraction of 98.127o on the silver and
88.4% on the gold. He believes that extraction of the
gold is less than that of the silver because the gold is
encased in the pyrite and, to liberate it, re-grinding
is imperative. But the ore contains only 5 grams of
gold per ton, therefore it remains yet to be proved, by
further experiment, whether it will be necessary to
re-grind more than 207o of the ore.
It was the custom formerly to use the camonero
to move the product of the Chilean mills onto the /)^//c,
where it was allowed to dry in the sun, but the change
to dry crushing will obviate the necessity for this prac-
tice. At the time of my visit, the Chilean mills were
being operated without screens, the discharge being
by overflow, thus saving labor while using a great
deal of water, of which there was plenty. The tires
on the Chilean mills are changed so as to equalize the
wear; they last two years; the dies last only about
eighteen months. Each mill requires 10 h.p. The
Fraser & Chalmers, or Union, type of Chilean mill,
modeled after Walker's patent, gives good service,
grinding 15 tons per day; those of other makers treat
only 8 or 9 tons, because the runners do not maintain
t i;
\ 1
t, i
f .u
■!!!«
152
AMONG THE MINES OF MEXICO
a vertical attitude. Seven Chilean mills ground 60
to 70 tons per day, while the Krupp ball-mill crushed
50 tons per day of 24 hours.
The product from the grinding machinery goes
to the barrel-room. There arc 13 barrels, originally
made by Allis-Chalmers and since modified on the
spot. Each barrel is beneath a hopper that holds a
charge of 4.7 tons. As this is filled by the cars (each
carrying half a ton) a grab sample is taken to deter-
mine the percentage of moisture and the richness in
silver ; from the aggregate of all these samples a mean
of the iron assay is obtained for the week, so as to
indicate if the amount be sufficient to effect precipita-
tion; if not, zinc is added in order to help precipitation
and also because it has been observed that the gold
recovery is better when zinc is employed in addition
to the iron. The cuprous chloride is proportioned to
the amount of -Mver amalgam in the barrel, decreas-
ing from, say, (>0% Ciu.CU at the beginning of the
month to 22 or 24::: at the end. The silver in the
charge is precipitated on iron. The barrel treatment
consumes eight hours ; it requires four hours to charge
and discharge. Mercury is added half an hour after
the treatment has begun. Salt is added in the ratio
of 27 kilograms per ton of ore ; no more copper sul-
phate is added than that required when making the
copper chloride solution. The loss of mercury per
month is 800 grams per kilogram of silver; the loss
of silver is 6.88 to 9% when treating three charges
per day.
THE BARREL PROCESS
153
The barrels are washed out once per month, dur-
ing the remainder of the time the silver amalgam
accumulates ir-He of them; it is taken out every
other day, in suon an amount as to yield 250 to 300
kilograms of silver bars.
From the barrels the pulp goes to six washers
or agitators, and from them to apuros (or wells) un-
derneath, where the silver amalgam is collected.
Thence the tailing passes outdoors to a crude form of
conical buddle. The 2,300 to 2,500 tons of tailing
treated each month contain 110 to 120 gm. silver per
ton and yield 25 to 30 tons of concentrate assaying
2 to 3 kg. silver and 30 to 40 gm. gold per ton.
When CU2CI2 is added, there is a formation of
AgCl and sometimes of HgCl; then if zinc (in the
form of strips of metal, not shaving) is added, the
metallic silver is precipitated and also the mercury.
Sodium hyposulphite was tried, but, although useful,
it was not found necessary. The purpose of it was to
regenerate the Hg from the HgCl formed, and the
same end could be gained by the motion of the pulp
in the barrel. If there is enough iron in the pulp, it
will precipitate the silver, but the amount of iron is
not under control, hence the addition of zinc if the
iron be inadequate. From the wear of the lining and
of the balls in the Krupp mill, Capt. Narvaez was get-
ting 600 gm. iron per ton of ore, this being the amount
which practice has demonstrated to be neces.sary.
Whenever, for any reason, the amount is less than
as specified, zinc is added. Experience has proved
1
] ii
u\t^^
154
AMONG THE MINES OF MEXICO
that, although 1,200 gm. iron is adequate to precipi-
tate the silver in a charge of two tons of ore and give
bullion 999 fine, yet zinc is always needed in order
to increase the gold recovery. If this be done, the bul-
lion will assay 960 gm. silver and 2.8 gm. gold per
kilogram, while, if the zinc be omitted, the gold will
not exceed one gram per kilogram.
The total extraction of silver by this barrel
process is 95% ; that of the gold is from 35 to 75%.
In the concentrate, 5'."' more of the gold is saved. The
gold is to the silver in the ore in tlie ratio of 5 to 1,000.
The ore treated at the mill is wjrth as delivered 23 to
25 pesos per ton, the cost of extraction {maquila) last
year was 10.50 per ton, and the profit 8 pesos per ton.
The ore assays generally 1.2 kg. silver, equal to about
41 pesos per ton.
The bulk of the ore obtained from the mines of
the Real del Monte Company is similar to ♦^hat treated
at the Hacienda La Union, although in the Corteza
mine of that company there is produced the class of
manganese ore called 'quemazones,' on account of its
black appt.irance. Such ore is not suitable for the
process o'' amalgamation because of the loss of mer-
cury, following upon the familiar reaction in which
a mixture of salt, manganese dioxide, and sulphuric
acid evolves the chlorine destructive to mercury. At
the time of my visit, this ore from the Corteza mine
went to the Hacienda de Loreto; it was a black sili-
cious material containing 87o manganese dioxide.
The treatment to be described has ceased lately, the
WW
%
•m'^
■flWita
REFRACTORY ORE
1 55
mill having been utilized to test the adaptability of
the cyanide process to this class of ore. At first the
idea was to erect a ball-mill, followed by a re-grind-
ing tube, as at La Union, but later it was decided to
install two sets of rolls, of the same dimensions and
running at the same speed, the first pair for reducing
the ore from 3 to ^-inch and the other for grinding
to 16 mesh; between the rolls there is a trommel, and
thence the material goes to the tube-mill. Trouble
was caused by the moisture in the ore, a coating be-
ing formed on the silex, requiring removal with a
chisel.
I shall now describe the process for which the
original plant was built; it was a modification of the
Francke process, originally developed in Chile. On
arrival, the ore passes through a Blake crusher and
then it is fed to the rolls, which deliver it to a trommel
provided with a 70-mesh screen; the undersize goes
to the bins, while the oversize passes to a tube-mill
{cilindro remolcdor), also made by Krupp, where it is
re-ground with flints {piedras de chispa) at the rate of
about 40 tons per day. Then it joins the previous un-
dersize in the bins. Next come four calcining fur-
naces, each with a capacity of 20 to 30 tons per day.
The charge of 10 tons is given 1 1/2 hours. Salt is added
in the proportion of 18 kilograms per ton of ore. The
calcined product drops below the furnace and is taken
in wheelbarrows to the cooling-floor. Here it is
shoveled into vats {tinas de Bolivia) where it becomes
mixed, through the agency of revolving arms, with
< I
mmm-
'S
i :
'V
156
AMONG THE MINES OF MEXICO
\ f '
cupric chloride (CuClj) and mercury. Copper plates
placed along the sides of the vats catch any gold in the
pulp. Each vat is 3 metres deep and 2>< m. in diame-
ter. During the treatment, steam enters through the
bottom. Three charges of nine tons each are treated
per day. Then, after four hours of mixing, the pulp
is discharged from these vats, through three openings
at successive levels leading into pipes that empty in
a mercury trap {apuro) outside. Here the silver amal-
gam is caught. The tailing passes on to two settlers,
without further addition of mercury, the purpose be-
ing to arrest any amalgam escaping from the preced-
ing operation. Below each settler there is an apuro,
which finishes the treatment.
Only one shift of 12 hoars (by day) is employed.
Two men attend to each furnace; these also do the
wheelbarrow work. Threemenattend to thepans; in
addition, there are two roustabouts and one foreman.
Each charge is not followed by a clean-up; the amal-
gam i^; allowed to accumulate.
The mill was idle at the time of my visit; it is
probable that there was a heavy loss through mineral
which was ground fine in the tube and then pulled by
the strong draft into the chimney of the calcining
furnace. Also there is likely to have been loss of silver
by volatilization as chloride.
The machinery is operated by electricity, and m
contrast to this flagrant modernism is the shrine in
the roaster-house, with its picture of the Virgin. In
other parts of the establishment there are crosses,
SHRINES AND SMELTING
157
decorated by withered flowers. Everywhere in the
hacienda there is an exuberance of masonry; the
works are enclosed by massive walls, like the ram-
parts of a fortress of the old-fashioned kind.
Such ore as does not contain manganese oxide,
and comes from the other mines operated by the Real
del Monte Company, undergoes direct concentration,
followed by amalgamation. This quartz ore is re-
duced by two Blake crushers and then passes to 14
Chilean mills, which discharge through 80-mesh
screens. The feeding is done by automatic (the
Hendy Challenge) machines. From the Chilean mills
the pulp goes to 32 Johnston vanners, which extract
the pyrite, not only to get at the gold that is inti-
mately associated with this pyrite, and to take out
half the silver in the ore, but also with a view to sim-
plifying the Patio process, which follows and which
would otherwise need the addition of more chemicals.
The 14 Chilean mills grind 800 to 900 tons per week;
the crude ore contains 1 kilogram of silver to 5 or 6
grams of gold; the pyritic concentrate represents 4
to Ay2 per cent of the crude ore; the richer concen-
trate, with 9 to 10 kg. silver and its proportionate
amount of gold, is shipped to Germany, while the
poorer, with 4 to 6 kg. silver, is sent to the smelters
at Monterrey and Aguascalientes.
The tailing from the vanners goes to big ponds,
where it settles to a thickness of 8 to 9 inches of pulp.
The camonero, or horse with the drag, is employed to
move the slime to the different rectangles in which
>? If
! 5
"I
l!l I
158
AMONG THE MINES OF MEXICO
the mixing stage of the Patio process is carried out-
There are 17 rectangles (50 metres wide and 80 m.
long), for the treatment of as many charges or tortus,
each being equal to 220 to 300 tors. The mixing is
done, not in the old way by horses, but with a me-
chanical harrow, such as has been described in con-
nection with the Hacienda Guadalupe. In this case
also, it seemed to me that the mechanical mixer failed
in its service; the material was too wet, the harrow
omitted to turn the palp over and simply passed
through it, without causing aeration. Moreover, as
the harrow cannot be made to scrape the floor, there
always remains at the very bottom an inch or more of
pulp, which is not moved and which, therefore, escapes
metallurgical treatment. The clean-up was done as
at the Hacienda Guadalupe, so that the description
need not be repeated.
The retorting is worth noting. The bricks of
amalgam are arranged in the form of a pyramid of
about one ton weight standing in an iron pan, the
bottom of which is perforated. A hood is then dropped
over the amalgam; a flue from the furnace enters
through an aperture near the base of the hood. The
mercury, as it is distilled, passes out at the bottom
into a stream of cold water, by which it is condensed.
The ratio of mercury to silver in the amalgam is as
8tol.
At the Progreso mill, which was built by that rep-
resentative Amfrican millman, M. P. Bess, there are
50 stamps, followed by four Kinkead mills; the lat-
t 1
!'■.
.1 -H
Two VlK\V> OF Mk\ (' KkATlNt; TIIK Pr.ANM.I.A AT PaCHUCA
(T\. ■ IT A
f^mff
THE PLANILLA
«59
tcr is a machine for re-grinding. Then come two
chemical mixers, 16 p?ns, and 4 settlers, followed by
4 New Standard and 6 johnston concentrators.
Just outside the mill I saw the Mexican method
of concentration by the planilla, or little plane. The
material is heaped up at the head of an incline plane.
8 to 10 feet long, 4 to 4J^ feet wide; the operator
throws the water with a horn, by successive regular
sweeps of his arm; at intervals he scoops up the ma-
terial with a wooden shovel, and as the heading be-
comes cleaned (or concentrated) he moves fresh ma-
terial to the top of the incline. Mexicans can be seen
operating the planilla along the beds of streams that
receive the tailing from the mills st Pachuca and
Guanajuato, as the accompanying; photographs show.
The device resembles the 'tyes' or straight buddies
employed for the treatment of slime in Cornwall.
Hi
'%
^
i
1 ' ft ! I • a
Cbaf ter 21
FIRST Gl.IMPSE OF GUANAJUATO— THE HISTORY
OF LOCAL MINING— THE \ ETA MADRE AND ITS
BONANZAS-RICH MINE-OVVNERS-THE COUNT OF
VALENCIANA— STORY OF THE CHURCH-DECA-
DENCE OF THE DISTRICT.
T is uncomfortable to arrive at
one's destination just before
(lawn, but sometimes the dis-
ci Mufort is not without compen-
sation. Owing to the wretched
train service between Mexico
City and Guanajuato (406 kilo-
metres or 252 miles), the trav-
eler reaches Silao at 1 a. m. and then, changing to a
branch railroad 14 miles long, he arrives at Marfil at
3 A. M., whence a horse-car bears him to Guanajuato,
a distance of four miles and occupying an hour. The
car is pulled by mules, at a sharp trot, along a winding
tramroad that follows the boliom of a ravine; there
are glimpses of high walls, dark archways, and silent
courtyards, an occasional hooded figure comes within
the rays of the feeble lamp at the front of the car,
other lights are infrequent; soon the tram penetrates
a thickly built town, the mules awaken echoes as they
scramble over the cobbles; the reverberations are lost
in narro , . alleys, but there is no sign of life, save the
EARLY MORNING AT GUANAJUATO
l6l
tired watchman who blows his whistle to prove him-
self awake and to prevent the other watchmen from
falling asleep — incidentally telling any prowler just
where to avoid him. The car goes up a steep gradient,
almost brushing the walls that look down on either
side, around sharp turns that threaten a capsize, over
a narrow bridge and along a stream flanked by
rustling trees. The journey is over. A friend conducts
me to a lofty wall, a dorr opens, we are in a moonlit
patio, in front of a white colonnade, in that light as
poetic as the moonlight itself, the effect of which is
Iieightened by a sound as of surf borne inland from
the shore; it seemed the voice of the distant sea, but
it was the .luffled roar of a starif-mill. However,
that rhythmic swell served to put ii' sleep, deeply
grateful for a little rest after the iit> 'ime travel of
tlie night. This was part of the compensation, but
tlie best of it came on awakening three hours later.
It was a sunny morning, with all the coolness
of the tiighlands and all the fragrance of the tropics;
going on the portico, I found myself overlooking a
' \vn behind which extended an array of steel vats
indicative of a cyanide plant; to the right were the
white-washed houses occupied by offices, and to the
left rose a loftier building — audibly, a stamp-mill.
The whole foreground was surrounded by a wall on
which the sunlight played gladly. Beyond were low
roofs and trees, rising on hillslopes, partly under cul-
tivation and leading to a brown ridge whose clear-cut
edge was silhouetted against the blue of a perfect sky.
i
^ J
K
'h ' H'l
162
AMONG THE MINES OF MEXICO
\t
It was the Hacienda San Francisco de Pastita, an old
Mexican reduction works, now transformed to mod-
ern methods, it was an island of Anglo-Celtic energy
in the midst of an old Spanish mining centre, and the
spirit of the men and the machinery of this new mill
of the Sirena mine was to the old era represented by
the decrepit town outside its walls as the invigorating
sunshine of this bright morning to the dark weariness
of my experience during the night that was past.
Guanajuato, in the State of the same name, is a
city of 50,000 people, situated at an altitude of 6,600
feet among the foothills of the Sierra de Santa Rosa.
The air is dry and clear, colors are vivid, lines are
defined, and the sunlight is brilliant. The town is not
without character, for it is adorned by many churches
and other impressive buildings; it lies ensconced
among terraced gardens and brown hills, on the
higher slopes of which stand the battlemented en-
closures and picturesque churches of historic mines.
Their story is worth the telling,'*
The history of Gunnajuato begins in 1526, six
years after the Spanish Conquest, when the mineral
wealth of Mexico was being eagerly sought out by the
hardy conqvistadores. To the north, the mines of
Zacatecas and San Luis Potosi had been uncovered;
the road to them, from Mexico City, passed near the
site of Guanajuato, but in those days it was danger-
ous to depart from the highway, for the natives, the
"And in the telling of it, I am indebted for many of my data to
Capt. W. Murdoch Wiley, who has studied the records.
^9"
««
«mi
FIRST DISCOVERIES OF ORE
163
Chicemecas, were unfriendly. A fort was built at
Santa Ana, and this became the first European settle-
ment in the region. Prospecting became more prac-
ticable, but no mineral discovery of importance fol-
lowed, until 1548, when the silver mine of San
Bernabe was discovered at La Luz, six miles from
the Guanajuato of today. Two years later rich ore
was found on the hills adjacent to the present city;
the Rayas mine being started by a Spaniard of that
name. The document that registered this fact is the
oldest in the archives of the Court of Mines at Guana-
juato. It was not until nine years later that the work
done at the Rayas and Mellado mines led to the recog-
nition of the mother vein, la Veta Madre. The ore was
mined for a width of 100 feet, so wide indeed as to
postpone further exploration along the course of the
lode. But the ore found by the Mellado shaft, in
1559, suggested the idea of continuity and caused an
extension of activity, so that it was not long before
mining operations were under way from the Tepeyac
to the Sirena workings. To those of us who regard
the discovery of the Comstock, less than 50 years ago,
or even the event at Sutter's Mill, 58 years ago, as a
historic event, it is worth noting that the happenings
briefly chronicled in the foregoing lines occurred be-
fore 1600 — before the first settlement of Virginia,
shortly after the sailor captains of Elizabeth had
swept the Spaniards off the seas, and just about the
period when Shakespeare and Bacon were busy pre-
paring documents of controverted authorship.
f
¥\
!H
I P\
h i
164
AMONG THE MINES OF MEXICO
By this time the population of the town had
grown to 4,000, and it continued to increase as vil-
lages sprang up around the individual mines. In 1619
the town was granted a patent, becoming dignified
by the name of Villa Real de Guanajuato. This was
a year before the landing of the Pilgrim Fathers at
Plymouth.
The industry grew; amalgamation was intro-
duced from Pachuca, the Patio process being first
employed at the Hacienda de Duran, just below the
Rayas mine. The best selected ore was smelted on
the spot and, considering the high grade of it, the slag
was surprisingly clean, for the remains of old smelter
dumps below the Rayas and Cata have been found to
assay only two ounces of silver per ton. Forced
labor, o' course, was employed, and two proclama-
tions ^ear testimony to the brutality of it, for one of
them prohibited the indiscriminate sale of Indians
and the other forbade the branding of a slave in the
face.
Within a century, that is, by 1700, the population
was quadrupled and the area of the camp was
doubled. Immigration was slow, for Spain was a
long way oflf in those days of uncertain sea voyages;
the transport of supplies was both laborious and
hazardous, the whole European population of Mexico
was still meagre, and mining methods were as yet
primitive. But the discovery of gunpowder and its
application to mining, the introduction of pumps and
the accumulation of wealth among the mine owners.
•'!',' 2)5
, jui,ij< . ..AtiJM.x mmrmr^m/fmmi
p»
nrnpF
MINERS THAT WERE ENNOBLED
i6S
r
all tended to enlarge the scale of operations until
Guanajuato, toward the end of the 18th century, be-
came one of the great mining centres of the New
World.
Tiie big mine owners won such wealth that, like
their modern successors in Nevada and Montana,
they became legislators and were given seats in high
places; they were granted titles of nobility and en-
livened the ranks of Spanish aristocracy. Jose de
Sardaiieta was created Marquis of Rayas; Francisco
Mathias, the owner of the Cata and Secho mines, be-
came Marquis of San Clemente and Viscount of
Duarte, while Antonio Obregon, the discoverer of
the Valenciana, became Count of thai name. It was
a great day for these mine operators. They were con-
sulted in affairs of State, just as nowadays men who
contribute to campaign funds are likely to possess
what Mr. Mike O'Flaherty trrms 'infloo-ence'; they
posed as Providence to the poor people, for when
times were hard and the corn crop was a failure, they
provided work for the needy and saved them from
starvation. It is said that the big galleries and com-
fortable cross-cuts, large enough for the passage of
a broad-gauge locomotive, tnat surprise the mining
engineer when he first visits Guanajuato, are the evi-
dence of work carried out with such charitable intent.
When an unusual bonanza was struck, the for-
tunate miner built a shrine or even a church, in token
of gratitude to his tutelary saint. Thus one Sarda-
iieta advanced an adit so as to cut the Santa Anita
*f'H!U.-
-ti
i66
AMONG THE MINES OF MEXICO
ore-shoot on its dip, but failing to reach this point
before he died, he told his son to continue the good
work. He did, and found the bonanza of Santa Rosa,
which made the Rayas mine famous. This Sar-
daiieta became Marquis of Rayas and erected the
monumental buildings whose flying buttresses and
sculptured portal, surmounted by the figure of the
archangel Michael, are today the glory of the San
Miguel shaft-house.
The church of Valenciana is another such me-
morial to successful prospecting. This edifice was
consecrated in 1778; though badly cracked in many
places and doomed to destruction, its fine harmonious
facade in carved can/era was rendered doubly impres-
sive when I saw it at the end of a day's investigation
of the old mines, and, mindful of a most romantic
chapter of mining history, watched the shafts of sun-
light suffuse the old church-front with a glory richer
than the treasure vault of silver that it commemorated.
The church was built by Antonio Obregon, a Spanish
miner, who discovered a great orebody north of the
Cata mine, in ground that had long been held to be
barren. He had thought otherwise and prospected
for three years, until penniless. Then a merchant
of Guanajuato provided some funds, until he too was
bankiupt. Oth rs were persuaded to share in the
venture, only to lose tbcir money, until Obregon
won the name of el tonto (the fool) de Valenciana.
But his justification came at the end of seven years of
persevering work, when he broke into the biggest
wmm
■p
M
4fP
Thk Flying Bittkessf.s of San Mir,i-Et. de Rayas
■
I'
^l\ ^
t
i
\iM
: i
lihi'^
\
A'-P
i
^\}^i
o
*^^ffflf?
■P^
THE CHURCH OF VALENCIANA
167
bonanza ever found on the Veta Madre. It was
much more than his fondest expectation, for, while
the Tepeyac had been worked in a desultory way
from 1590 and the outcrop of that vein in the Valen-
ciana ground has yielded some ore, it is doubtful
whether any such ordinary body of mineral could
have repaid the long and expensive search made by
Obregon and his backers. In a few months all the
expenses of years were repaid and eventually Obre-
gon became, the chronicle says, the richest man in the
world, at that time. The immediate origin of the
church is told thus: On the ground near the mine,
Obregon marked out an irregular quadrangle within
which the miners were told to place a handful of rich
ore, which each man was allowed, for this exceptional
purpose, to bring out of the mine. It was a custom
that recognized the innate tendency of the miner to
purloin a little — a specimen or a sample — of the rich
ore that he was helping to extract; and by requiring
his men to donate that larcenous portion of mineral
for the benefit of Holy Church, Obregon was finally
able to do a great deed without unduly taxing his own
receipts. The quadrangular area as marked was
eventuSiy covered three feet thick with rich ore; this
was sold and the proceeds of it were employed to build
the church. It was begun in 1765 and finished in
1785; it is said to have cost $1,000,000, which was
about equivalent to the annual income of Obregon.
He made gifts to the Crown and, becoming the
wealthiest subject of Spain, he was made Count of
jl V 1
■ t. ■ r
i68
AMONG THE MIXES OF MEXICO
Valenciana. This was at the time of the American
revolution, and since then we have had many a Monte
Cristo among mining adventurers, a motley crew of
ill-balanced men, from vulgar spendthrifts like Tabor
and Barnato to great-minded builders of empire like
Cecil Rhodes and Alfred Beit.
mm
'M
'■■•■■ill
nil
f
J u i .i ' .■■t- pry"!g*''^wPffgB— wgjgw!
chapter 22
GUANAJUATO AT ITS HEIGHT — DEEP MINING —
VISIT OF HUMBOLDT- DECADENCE— LA LUZ— THE
REVIVAI^AN AMERICAN INVASION— THE STORY
OF MODERN PROGRESS.
T the end of the 18th century
the mines of Guanajuato were
the foremost of their kind. It
was then that the Valenciana
shaft was sunk to 1,800 feet, and
it is still the deepest in the dis-
trict. This work, done by Obre'
_ _ gon, was completed in 1785 at a
fabulous expense. It is said to have cost a million,
though even this expenditure becomes small rela-
tively to that of the Combination shaft, sunk on the
Comstock lode, in 1881 ; this was 3,100 feet deep and
cost $6,000,000. However, the cost of the big shaft
of the Valenciana was offset by an extraordinary pro-
duction, stated at 300,000,000 dollars, most of it ex-
tracted (Jfiting the la^t half of the 18th century. This
figure corresponds to the total output of the Com-
stock up to the time when the lower workings were
abandoned, in 1884. On August 20, 1804, the King's
tax, amounting to the sum of 2,648,866 dollars was
paid. As this represented one-fifth of the yield for a
period of five years, it serves to substantiate even the
^^
mmfimm
r-^^-.
m
It •; i
! i^
{•>-i| l/i
I/O
AMONG THE MINES OF MEXICO
extraordin.iry statistics of these old mines. The other
mines on the Veta Madre and those on the La Luz
veins also produced enormously at this period, so
that the population of the district at the beginning
of the 19th century had increased to 100,000. This
was the time of Humboldt's visit. He says that "the
whole vein (the Veta Madre) of Guanaxuato" may be
estimated at four ounces of silver per quintal of mine-
rals." As a quintal is 100 pounds, this means ore aver-
aging 80 oz. per ton of 2,000 pounds.
Then came the long years of the revolution
against Spanish domination. In 1810, when at the
height of her prosperity as a mining centre, Guanajuato
was attacked by the Republican forces under Miguel
Hidalgo, a priest, who became the hero of the Mexi-
can war of independence. There was desperate fight-
ing and the city was captured. The entire fabric of
government and of business went to pieces. The
warring factions made forced loans on the min^^s,
horses and provisions were wantonly seized, life be-
came insecure, so that mining operations were dis-
couraged and all work of importance was discon-
tinued. Deep work ceased entirely, no shafts were
sunk, and the production of ore was reduce* to infie-
quent shipments taken from supporting pillars and
from the sides of old stopes. Even such decadent
mining soon became insignificant as the miners were
driven toward the surface by the slowly rising water.
' It is always spelled with an x in Humboldt's memoirs.
I' M l\ fk A .. WWPIF'^EgBaiWIP'Wgg
z
PT'S*
iH
\\u
' '■ |!.1
i\
DURING TH! REVOLUTION!
m
it was at this period of general lawlessm ^ that the
heavy wails wi'h watch tov ers vvere bui.t .round the
mini"^. ui til v ci property of consequcr ha'' lue
look oi ' fonress. Simiiar pro'cction was pivi.n to
the reduction w irk, which be me fonitied enclo-
sures, tor the p.No.^ .vere frequ^inly rofi ed ■' their
c!' rin-up * roviiig !• nds ' lonq^ing to both tactions,
viichm hener**ss)ties< th* r organization an ex-
tor a .rener;
battlcnu-nte''
anajuato an
;nd afford
ronia "ic tiii
velvc '■^ 1'
in th wr.ii
r. >pi-!
th*- in
en. '1' pillage and munier.
IS survive in the vie ty
ue- this • riod of law!
etting to mti es
traditions.
Spanish rule
the first Mexi-
^qi
,r eai
-cd uefore
of Iturbide
a; Mexico City, on Jul.. 21, 1822. '~>ur
nl the population of Guanajuato d in
Til
of 1
ncs>
• ca
ci-i
r
iiu
died t 2( AAj md mining almost ceased. Wit'- he
■■e<?toratio! of order, the mine-owners set to to
rehabilit their properties. Among the m
Don Lucas Alainan, who represen
ic : ♦he Court of St. James, and wa
ic be. ver in the mineral v/ealth of Gu
le in? rested English capitalists in . =>
with the result that two large companies
were f rmed, the United Mexican Mining Association
and the Anglo-Mexican Mining Company. They ac-
luired several of the bigg^-^t mines on the Veta
.""'.drv lesides others of the '.'ierra and La Luz sys-
u is. The old workings were unwatered and the
[iri'in:
nc
cm
ju;>
schemi s
I a
17a
AMONG THE MINES OF MEXICO
w
,)7\
^1]^ it'
II ■
m!'.ls were renovated. But it was not smooth sailing
for these EngHsh companies, there were periodical
local insurrections, life and property were still inse-
cure, and mining was attended by many interruptions ;
for example, in 1832, one Ariste, at the head of a 're-
generating army,' or ejercito regeneradoro, swooped
down on the Rayas mine, then the property of the
United Mexican Co. and lifted silver and corn to
the value of 26,000 pesos.
The mines of La Luz were in bonanza in 1842 and
for many years after, so that Guanajuato itself be-
came less important, but twenty years later Francisco
Glennie took charge of the Rul estate and by his skill
he made these mines on the Veta Madre more pro-
ductive than they had been at any time since the
palmy days at the close of the eighteenth century.
The Valenciana was unwatered to the bottom at
1,800 feet and a new orebody was discovered in the
Merced" vein. At the same time Glennie developed
the Cata mine and found the rich Juanita" vein.
When he became invalided, in 1890, another period
of depression ensued at Guanajuato. All the com-
pany work at the Valenciana was stopped and the
water was allowed to rise. At the Cata, the
water was kept down, but here, as at the Valenciana,
the workings were handed over to the tender mercies
of the buscones. These are 'tributers' on a small scale;
they take a lease from week to week without any writ-
" These were speci.nl segregations of rich ore in the Mother Lode.
nP9B
ENERGETIC PROMOTERS
J73
ten contract and divide the ore they get with the
mine-owner, who provides the tools, powder, and
blacksmith. On each Saturday morning the buscon
sorts his ore, arranging it in two equal piles, of which
the foreman takes his choice on behalf of the owners
of the mine. Of course, the buscon cannot aflford to
explore, he does no 'dead work' ; and as he moves no
more waste than is necessary, the workings soon be-
come choked with refuse. He nibbles at every pillar
left to support the old stopes, and causes caving that
will close the mine or portions of it, permanently.
And so mining came down to a dreary unprogres-
sive level, with no new work and no fresh discoveries
of ore, until, in 1898, another revival was inaugurated
by the f iterprise of a few Americans. In that year
the Guanajuato Consolidated Mining & Milling Com-
pany secured the Sir na mine and erected a modern
mill, under the direction of Mr. M. E. MacDonald,
assisted subsequently by his brotlser, Mr. Bernard
MacDonald.
In 1902 the Guanajuato Power & Electric Com-
pany was formed by a group of mining men at Colo-
rado Springs, on the initiative of Mr. Leonard F.
Curtis; he was ably supported by Messrs. George
Bryant and George W. McElhiney, to whose financial
ability are due several of the most important enter-
prises in the district. As fuel of any kind was very
expensive, the introduction of power at a reasonable
price was an important step in the progress of min-
ing. This was accomplished in November, 1904.
I i
1
1
174
AMONG THE MINES OF MEXICO
J
•n
The electric energy now used at every large mine in
the Guanajuato district is obtained from the river
Duero, in the State of Michoaca... 101 miles distant.
This power at 185 pesos per h.p. year" replaced wood
at 8 to 10 pesos per metric ton and stone coal, from
Las Esperanzas, in Coahuila, at 20 to 24 pesos,
delivered.
The next enterprise of importance to be started
was the Guanajuato Reduction & Mines Company.
The history of the mines that it acquired has been
mentioned; they included the property originally be-
longing to Obregon, the discoverer of the Valenciana,
and from his descendants by intermarriage they had
passed to the noble family of Rul. In 1860 the Sefiora
Perez Galvez, then head of the house of Rul, began a
clever campaign, the purpose of which was to obtain
avios or perpetual leases on these mines, including the
Valenciana, Cata, Tepiac, and Mellado. By the avio
she was able to charg<» all expenditures against the
mines, crediting them with the money received from
the sale of ore; by building large works or haciendas,
bhe made contracts with herself to purchr v the out-
put of ore, deducting high rates for trec»..nent and
mixing the rich with the poor ore, ^o that the expenses
of mining were always in excess and steadily in-
creased the debt against the mines, while permitting
of handsome profits at the haciendas. The options to
these contracts or avios were acquired by Messrs.
" This is the average price. The lowest price in the dist- ict today is
$60 per h.p. year.
-'^a^ene
i*^.-a _ /
THE AVIO COl TRACTS
175
Bryant & McElhiney, and transferred by them to the
Guanajuato Reduction & Mines Co., which finally
bought them outright. According to Mexican law,
if at any time the mines get into bonanza, so as to
make big profits from the sale of ore, the lessee has
the right to take all such profits, without any division
with the owners, until the entire accumulated debt —
about six million pesos — is paid, thereafter dividing
the further profits according to the terms specified
in the lease; in plain English, the original ownership
is a legal figment. Besides acquiring these old con-
tracts, the promoters mentioned had the foresight to
'denounce' or 'locate' claims covering the dip of all
the important properties on this part of the Veta
Madre; that is, they secured the 'deep levels.'
Finally, after expert examinations and reports had
been made by such men as Carlos Van Law, Robert
T. Hill, and Louis Noble, these properties and all their
rights passed under the control of the Guanajuato
Reduction & Mines Co., in November, 1904.
Since then other ventures have been organized
and started, but their story is in process of making
and must be left to a later record.
While the peso today is worth about half of a dollar, before the
(lomonetization of silver they were about equal, for each contained about
an ounce of °ilvcr.
I
-. -f-^^ »■'»'« ' ^KBTSSf.
f\^
» "■' *
copter 23
VISIT TO THE OLD MINES— A CAVALCADE— THE
BUSTOS PLANT— MECHANICAL DEVICES AGAINST
MANUAL LABOR— THE MOTHER LODE — SAN
MIGUEL DE RAYAS.
N the morning of November 2,
a party was made to visit the old
mines of the Veta Madre. We
formed an imposing cavalcade,
for it is the custom in Mexico
for each horseman to be accom-
panied by a mozo, who serves as
groom on ordinary occasions,
and is a courier and general servant when going
across country to the mines at a distance. These
men wear the wide-brimmed sombrero, fancy leggings,
and big spurs, so that they are picturesque if nothing
else, and on an occasion of pleasure snch as this was,
they gave a touch of gaiety to a group of horsemen,
most of who were as properly accoutred as in
Chapultepec or Central Park. There were ten of us,
and eight mozos, so that when we clattered down the
narrow cobble-paved alleys of the old Mexican town,
we made noise enough for a regiment, scattering care-
less wayfarers and awakening echoes under arches
that had seen many inv?sions murh less peaceable.
The well-bred Mexican is a splendid horseman, but
the inhabitants of such a town as Guanajuato are, of
if \
I v.
w
-'za^-'i'.mKk"
Amonc, Friknds at Gl'anajuato
C, W. llrya.it. Bernard MacDonal.i, T. A. Hickar.l. F. J. Ilot'si.n. 1). J. Hutton,
C. W. Van Law, M. ¥.. MacDonalil. Norman Ko*e.
m:-'
it.
*i
StkKI. OkE-HiNS ami liMTKKV lolMiATlONS (II THE BlSTOS MiLL
THE BUSTOS MILL
-^n
course, content to go afoot, so that accompanied as I
was by a group of engineers and metallurgists, it
occurred to me that there was a simile to be snatched
from the scene, the technical man being the fellov
on horseback, progressing confidently (usually w
less noise), while the rest of the world is content p >
force to go on foot. Well, my friends rode several
hobbies, not to mention spirited steeds; one of them
was the application of the cyanide process to silver
ores; and their horsemanship was good either way.
On arrival at the lower end of the town, I was shown
the Hacienda de Bustos, where the Guanajuato Re-
duction & Mines Company is remodeling an old re-
duction works to the needs of a modern equipment,
as the accompanying photograph will illustrate.
This hacienda is about a hundr-d years old ; in pulling
down the walls to make room for the concentrator
floor, there was found a system of older unconform-
able foundations, and in the angle made by two walls
of ancient date, the workmen unearthed half a dozen
complete skeletons, with a bullet hole in each skull,
and so placed as to indicate that the originals were
pistoled while lying down. However, this gruesome
find did not hold our attention long, for the founda-
tions of the new stamp-batteries and the steel framit g
of the ore-bins afforded more cheerful subject for
thought.
In the erection of the Bustos plant, bedrock was
everywhere available, and the heavy masonry walls
were built cheaply by Mexican labor, which is par-
178
AMONG THE MINES OF MEXICO
ticularly skilled in such work. Each stamp weighs
1,050 pounds. The mortars are of El Oro type and
weigh 9,000 pounds; they rest upon massive concrete
blocks laid in Dyckerhoff cement. The concentrator
room is spacious, being covered by a well-designed
roof-truss of steel construction. The tailing from
the Wilfley tables runs into a concrete launder, which
extends down the longer axis of the concentrator
room to the centre of it, delivering its contents to a
tunnel at right angles and thence to the cyanide
annex. While the plant was in course of construc-
tion, a 5-stamp battery, with its cyanide annex com-
plete, was being employed for testing the various ores
destined to be delivered to the works when finished.
Even when the 80 stamps are at work, this small addi-
tion will be kept in service, for experimental purposes.
In the concentration department of this testing plant
there is a Wilfiey table, a Gilpin county bumper, and
an Overstrom table. After being crushed under the
stamps, the pulp passes over one of the three ma-
chines just mentioned and then to a sump, whence it
is pumped 60 feet to cone-separators. The sand
undergoes percolation in vats 8 feet deep and 8 feet
diameter, provided with, the Butters hydraulic dis-
tributor. The slime is agitated in vats 9 feet deep
and 8 feet diameter; one vat using the Hobson aero-
mechanical agitator nnd the other a Butters pump
with mechanical stirrers. Thus the testing plant is
designed throughout to duplicate the conditions
under which the big mill is to be operate .
- - 11. -^TS- \iliiii ■ VI- 1 livmiaii^ ■IShB'iK'MiBes&RXtii
rs"
Thk Ga'Eway of the Rayas Mine
= "ffiKB iSHt'.j'is^'aara' ^.rw, ■
ill'
m
1
\
4*^'
1 '■■
J 1
■ : ■
- \
'^
%
i • ^=r:i . \ -
4
^ -,v_ ■..■■S
4
^■^^ ■' " T-4L I ' ^^^^K^H|^^^PHi^H
! n
» i i
iWt
i
•II
f
fcA^t
y^w%
STEEL ORE-BINS
179
The Bustos mill is planned so that it can be
doubled conveniently; in fact, excavations for that
purpose were under way at the time of my visit. A
sufficient space will be cleared at the back of the ex-
isting plant to allow of the erection of a second row
of 80 stamps on the other side of the bins. A concen-
trator room, identical with the existing one, will be
added, so a^ to make the plant a 160-stamp mill of
back-to-back construction.
Owing to the high price of American lumber
when delivered at Guanajuato, and the poor quality
of the Mexican material, it is considered economical
to use steel. The skeleton of the bin is of 15-inch
channels placed back-to-back in bents that are on
approximately 6-foot centres, the vertical channel
posts being tied together at the bin-floor level by two
15-inch channels, which are braced from the feet of
the posts by inclined struts composed of four 5 by
3^ by %-inch latticed angles. The thrust that these
inclined struts carry to the feet of the posts is taken
by two 8-inch channels acting as a tie between the
feet of the posts, thus trussing the whole and making
the strains on the masonry wholly vertical. As the
weight in the bin is about 2,500 tons, exclusive of the
bin itself, the feet of the columns are supported upon
a grillage of six 5-inch I-beams, two feet long, held
together by platen riveted to the top and bottoms.
This rests directly upon the masonry. All the bents
are braced together longitudinally at the top and
floor-level of the bin by 8-inch channels and heavy
i8o
AMOMG THE MINES OF MEXICO
n H
angles : a* the ends of the bin the outward thrust upon
the bents is taken by a truss-member at the top of
the bin. The bents themselves are tied together at
the top by -)4-inch plates 4 inches wide, riveted be-
tween the channel-beams to the posts. Within this
skeleton is a lining of plank, 4 inches thick in the
bottom courses, with an inner sheathing of 2-inch
plank having the grain vertical. The bin has a flat
bottom supported on 4 by 14-inch joists on 12-inch
centres, carried upon horizontal members of the
steel bents before mentioned, on the top of which
is laid a 3-inch plank covered by a 2-inch lining. The
entire construction does credit to the manager, Mr.
Carlos W. Van Law.
While V e examined the mill, an interesting dis-
cussion arose regarding the comparative value of the
mechanical conveyor. Cars were advocated as
econotu'cal because the cost of power alone (apart
from repairs to the conveyor, maintenance, and in-
terest on capital) exceeds the expenditure for labor
when employing cars plus human labor. A conveyor
requiring 7 h.p. at $7 per h.p. month is equivalent to,
say, $50 or 100 pesos per month. The same work
can be done by two peoncs at 50 centavos per day,
equivalent to 30 pesos per month. In case a peon
wears out, you can get another without absorption
of capital! But alas for such calculations, the peon
does not work on feast days. There is a great ad-
vantage in employing machinery that goes forward
without any stops. For in Mexico there are 25 fiestas
THE MOTHER LODE J*
per annum that are rigidly observed, besides Sum! ./
and San Lunas (or St. Monday— sacred to sober: ig
observance), so that there are at least 75 days •{
interruption in a year, and wherever laborers are n- >t
plentiful, this feature must be taken into recount.
On the other hand, if one has a bin capable of holding
a ten days' '.i p^ly of ore for the entire plant — as is
the case at the Bustos mill — the bad effect of two or
three days of fiesta is obviated. Of course, where a
car-track is impracticable or where elevating is re-
quired, the conveyor holds the field — and that is
often.
Leaving the Hacienda de Bustos, we rode up a
ravine leading to the mines on the great lode of
Guanajuato, called the Veta Madre, a term which in
the guise of 'Mother Lode' has also been applied to
the main vein-system of California. In the State of
the Argonauts it refers to a general zone or belt sev-
eral miles wide an-' ^"^ miles long, but at Guanajuato
it defines a distinc : ar -hannel about 600 feet wide
and seven miles kv .> he foot of the hill on
which stands the 1 .v a<; iv- i e, the Veta Madre ■'.
crossed by the Canoi ■:■ 7'.; '/te, and a natural scic
of the big outcrop is visi»)U . The lode consist \i-it >.
eight feet of silicified breccia; on the foot-w<"' > v
posed in the bed of the stream, there is a quartz vein
traversed by black streaks of argentite that dip at
45'; and under this ore comes brecciated schist
cemented by quartz, the latter diminishing until the
schist exhibits a ramification {ramillo) of stringers,
.
•fj
ii '
mi
182
AMONG THE MINES OF MEXICO
the dominant members of which are parallel to the
foot-wall. Beyond this point, the quartz continues
to decrease, and on the farther side of the stream the
schist appears in the regular laminae to which it owes
its name of hoja de libra, or book-leaves. This is the
main foot-wall country.
Remounting our horses, we returned down the
caiion, soon reaching the Rayas church, a beautiful
remnant of the loving architecture that the Spaniard
lavished even on his mines. In these churches are
found all sorts of queer pictures celebrating the
thankfulness of the donor for deliverance from vari-
ous perils. In them the miner testified to the danger
of his calling, by the tribute offered to his particular
saint.
Ascending the hillside overlooking the church
and its environing buildings, we turned to look on
the crumbling walls of an old hacienda, which we had
failed to notice as we rode past it. The walled en-
closures seem inadequate for protection, and yet they
served their purpose before long-range rifle practice
was developed. Until about twenty-five years ago,
brigandage was so rife in this, as in other parts, of
Mexico, that the haciendas or reduction works were
periodically 'held up' by outlaws, particularly in out-
lying districts. As regards Guanajuato, their special
nest was at El Capulin. on the road between Silao and
Marfil. They terrorized the country, and despite oc-
casional raids from the military, who drove them
into the hills, the bandits would return after a short
l^,i^^^^^
■^
THE RAYAS SHAFT
183
^md:
interval, to resume their depredations. Finally, in
1883, the State Government sent a body of mounted
police to attack them. Sixty men were captured,
placed against a wall, and shot. El Capulin was
completely destroyed ; not a hut was left to mark the
spot. That ended the business.
Passing close to the flying buttresses of the mag-
nificent walls that enclose the San Miguel shaft of the
Rayas mine, we entered the old enclosure. A sug-
gestion of the appearance of this architectural sur-
vival is presented by the photograph facing page 167.
A little farther and we entered the courtyard of
the Rayas shaft, one of the four great openings on the
Veta Madre. This one is octagonal in shape, and 38
feet in diameter. The depth is 1,400 feet. Why
these shafts were so big and the manner in which
they were operated, will be told in the sequel. They
make even the most self-confident American miner
realize that his science did not begin at Virginia City,
nor was it born in Colorado. The Rayas was sunk
by the Spaniards in 1850, while the Valenciana shaft
is a hundred years old, and yet one can read in the
Mininff and Scientific Press of forty years ago that there
was jubilation on the Comstock when the Ophir shaft
reached 400 feet, and that doubts were entertained
whether there would be machinery able to cope with
any greater depth. Yet eventually the men of Ne-
vada went down 3,250 feet.
■«■ l;
-m
Ml
I
■ft n I
(T^^ter 24
A GRAND VIEW— REMINDERS OF A FORJVIER TIME-
ENGLISH ENTERPRISE.
ROM the stone balcony or
mirador of the Rayas mine, there
is a splendid view of the country
around Guanajuato. I shall try
to describe it.
In the distance to the left,
the bold ridge of La Bufa, a
scarp of rhyolite tuff, is sil-
houetted against the clear blue sky. Under the
o\'erhanging brows of these cliffs and protected from
the weather, there are figures of heroic size painted
on the rock: they represent a red devil and his retinue
tempting the Christ. In the cavern adjoining these
are several paintings of St. Ignacio and the Virgin,
done i'i color with as much skill as the similar work
to be seen in the churches. This mountain top — from
which may be seen Guanajuato, Silao, Leon, ond the
wide expanse of the rich Bajio — was supposed to
suggest that from which El Salvador was shown the
kingdoms of this world and their glory, in the great
temptation. Lower down, near the talus slope, the
ether temptations are depicted in a crude way. It
is not said that the riches of the Vcta Madre were
f I
MEXICAN ARCHITECTURE
I8S
offered; they have tempted many men to their un-
doing during the last two hundred years.
On the rounded foothills that extend from the
base of La Bufa begins the residence portion of
Guanajuato; it is called La Presa, because of its
dominant feature, a big dam with an encircling park.
Seen from a distance, there is a gleam of pink walls
among cedars ind the tops of some church-towers;
then th€ crest of a ridge intervenes. At the foot of
this and in the cafiada below the Rayas, there is a
cluster of brown ruins, La Duran, the rildest hacienda
de beneficio in Guanajuato, and contemporaneous with
the discovery of the Patio process, in LS.S7. A hun-
dred vards below it, the bed of the stream is crossed
by the slender line of an aqueduct, which now serves
to carry the pipe-line that brings the water-supply of
the town. The six pillars are capped by a series of
broad keystones, which do duty as arches. This is
a characteristic typo of Mexican architecture." Be-
low the aqueduct, the Canada turns to the right and
becomes fringed by Peruvian pepper trees, and beyond
them is the big hollow in which the town of Guana-
juato lies huddled — a multitudinous complex of walls
—pink, yellow, and white — with red Moorish cam-
paniles. The narrow river-bed is marked by a con-
"* The 'flat arch' is held by some to be the oldest and simplest expedient
for supporting a structure ; it is supposed to h.ive originated from the big
stone placed over a doorway in the days before the idea of the true arch
was (levp:oped. Other engineers, for instance Mr Carlos Van Law, are
of the opinion that the flat arch was a drvclopment from the true arch,
and thnt, in form and principle, it is the roa! origin of our modem inven-
tion' of fire-proof floor construction with its so-called arch-tiles.
i86
AMONG THE MIXES OF MEXICO
gestK "own walls; on the onlooking slopes
the ;ase in the density of building and an
inci . v-erdure, until the top of the ridges s
reached, where there are no dwellings, but only the
dark red earth of the cornfields, defined by hedges of
organ cactus. Surrounding the town and o^'erlook-
ing it, are golden brown hills, with contours deeply
eroded and steep ravines, the culminating point being
the cone of Cubilete. The broken sky-line is carved in
diabase, and the nearer slopes are eroded in the con-
glomerate that lies on the flanks of the main ridge.
In front, beyond the huddled habitations of man
and the brown hills, crossed by the traveling shadows
of clouds that fleck the vivid blue of the sky, stretches
the purple interval that marks the Bajio. a great
valley along which runs the Mexican Central — an
unromantic railroad, with slow trains, sloppy Chinese
cooking, and a most distressing service. Beyond it,
like the good things promised on the other side of this
vale of tears, is the blue line of the Cordilleras, throb-
bing with soft enchantment and pulsating with the
romance of mining that shall not die.
When luncheon was over we left the mir.idor, and
in doing so passed through the remains of a pretty
garden. It seemed strange to see the old-fashioned
gilly-flower, rose bushes, and violets among these
mine buildings. They had a story to tell of the Eng-
lishmen who planted .them. There was a time, from
1824 to 1850, when English capital irrigated the min-
ing camps of Mexico, and among them Guanajuato.
^gua- ^im
1»^A^
REMINDERS OF ANOTHER DAY
187
Owing to the costly methods of operation, the attempt
to employ only the comparatively expensive imported
white labor, and th*- lack of expent'nce in treating the
silicious silver ores, these early efforts were generally
unprofitable, although with their characteristic
dogged determination, the English companies con-
tinued to operate the mines, with steadily diminishing
intensity, for many years. While aetive work on any
important mine ceased fifty years ag^. they held on
to the San Cayetano until within a few months, when
that property was transferred by the Utt»ted Mexican
Mines Association, Ltd., organ'.'.ed in ISU, to a new
American company. Between the English period,
already defined, and the present American dispensa-
tion, there was a good dea' of work done under Mexi-
can companies, although these lacked the t^nterprise
of the heroic days at the very beginning of the nine-
teenth century.
(T^ter 25
iKau.i;
THE GREAT SHAFTS OF THE VETA MADRE— THE
RAYAS — THE CATA — THE TIRO GENERAL — WHAT
BRYAN SAID OF IT-HOW IT WAS UNWATERED—
A WONDERFUL SPECTACLE.
HE four great shafts on the
\'eta Madre are the Rayas, the
Cata, and the two pits of the
V'alenciana, namely, those of
San Jose and Guadalupe.
The Rayas is octagonal and
38 feet in diameter, with a depth
of 1,400 feet. Among the old
machinery to be seen near-by is a Cornish hoisting
engine of 1835 built by Harvey & Co., at Hayle, Corn-
wall; alongside are two Lancashire boilers. In an-
other building is a first-motion hoist built by the
Union Iron Works, of San Francisco, in 1866; it is
one of the best of the old style, with jaw-braks and
flat wire-ropes. The head-frame is built with timber
struts footed in cemented masonry. This was erected
in 1887, when the Rayas mine was unwatered. Rut
there is a suggestion of methods used long before
even this old machinery was set to work; the sites of
the horse-whims used by the Mexicans is marked by
a tablet inscribed to the patron saint of each operator.
THE CATA SHAFT
189
One, for instance, reads "San Francisco. Nov. 1,
1820."
The Cata shaft is 280 metres, or about 925 feet,
deep and 20 feet wide. At the collar, and for 50 feet
down, it is octagonal, with sides of masonry. I went
down in a cage running on wire-rope guides, which
gave one a feeling of detachment, for in places, below
the portion that is lined with masonry, the pit is 30
to 40 feet wide. A native boy held a torch to illu-
minate the distant sides of the shaft. The torch used
in the mines is worth describing: It is called a mecha
and consists of 40 native candles, made of tallow arid
yarn, which are pounded into a mass and wrapped in
a cloth with wood splints to stiffen it. Outside of
this is a wrapping of riata or twine, obtained from the
maguey plant. The torch is two feet long and 2>4
inches thick; it is wetted outside, so that the tallow
will coneeal as it drips. By the light of it, when we
reached the bottom of the shaft, we saw the Aldrich
quintujJlex - -mp, made by the Allentown Rolling
Mil'. V'ennsylvania. It consists of a battery of five
vcr; . plungers, all the five cranks inside, with two
post-bearings outside. This pump is said to be doing
good work, lifting 300 gallons per minute to the
drainage adit, 880 feet overhead.
The San Jose shaft was also known as the tiro
general or general shaft of the Valenciana ; it has been
mentioned already in recounting the enrly history of
(Kianajuato. It is an impressive hole. There is none
like it. It is octagonal, ?3 feet in diameter and lined
■^ JJ^ g SLi -
^^-
»M
190
AMONG THE MINES OF MEXICO
with masonry for 100 feet. The bottom is at 525
metres or 1,730 feet. Water-level stood at 198 tretres
or 650 feet at the time of my visit. This is the shaft
of which it was truly said — among others, so I was
informed, by Robert Bunsen at Leadville in 1881 —
that a man can read his paper at the bottom by the
light of the sun, because here in the tropics during the
summer solstice the sun for two weeks is vertically
overhead. Early in July, the mist caused by the sun's
heat striking directly on tlie water at the bottom of
the shaft, causes a beautiful rainbow every day at noon.
This is the shaft also of which William Jennings
Bryan — who visited Mexico after his first silver cam-
paign and was royally entertained — said, that he had
never before seen a hole big enough and deep enough
to bury the gold standard. But he said nothing at all
about the shallowness of the oratory of the river
Platte! However deep the shaft may be, it will be
filled up some day unless tourists are forbidden a
near approach. From time out of mind it has been
deemed great sport to throw stones down this vast
pit and listen to the reverberations. I offered my
tribute to the Tiro General. First one hears the
sound of rushing wind — the echo of the passage of
the stone through the air; then there comes a roar
as it strikes the side of the shaft, and this is followed
by a crash as it hits the water, (in the light of later
events, here in San Francisco, I can te'l my friends
at Guanajuato that these sounds resemble the on-
3
I HK (IkKAT Sn\hT (IK THK V.M.KNllANX,
l.(H)KiN(: Down; thk. Sin Is KHKLECTto
BV THE WaTKR at THE BoTTOM
/■^<n^-^
■*■■: 4.
Il t
I: i
¥i I
l«M-ti
:f
t
- Ji
/. —
a .^J
nMHB^
THE TIRO GENERAL
191
coming of an earthquake, to anyone living near the
actual line of faulting.)
The shaft is octagonal, this shape being due to
the method of hoisting prevailing at the time it was
sunk. Around it, at a radius of 150 feet, can still be
seen the ruined gables of the eight houses, each of
which contained a malacate or horse-whim. A malacate
is said by the Mexicans to be operated by juerza de
sangre or force of blood, as compared to the fuerza de
vapor or steam-hoist. The typical malacate employed
in this work was usually a vertical drum of oak or
mesquite, from 12 to 16 feet in diameter and 12 to 14
feet high, with a wooden central axis supported on
iron gudgeons, top and bottom. The lower end of
this drum was about three feet off the ground and to
it were fixed four heavy mesquite sweeps of 15-ft.
radius. To the end of each sweep were harnessed
four horses, in crude rawhide harness, driven by a
boy (seated on each sweep) at a gallop around the
circle. Originally a hemp rope— later, a steel cable
—was wound eight or ten turns around the drum,
both ends depending in the shaft and hoisting in bal-
ance. The trip completed, the horses were reversed
on the sweep and the return trip commenced. As,
with the depths worked, the empty bucket, plus rope,
considerably overbalanced the load when the latter
neared the surface, the driving boys usually had to
hop down from their perch toward the end of each
trip and restrain the motion of the drum by holding
IjP
'.}.f-':
MICROCOPY RESOIUTION TEST CHART
ANSI ond ISO TEST CHART No 2i
1.0
I.I
Iflli^
1^
2.2
[2.0
1.8
1.25
1.4
1.6
_J /AP PLIED IIVV1GE Inc
I ™ '6^? Lo5t Ma.f' ".'-e^t
f.= Roc^iester, Ne« ■'O'k 1*609 uSA
"■^S (^'6) *82 - 0300 - Phone
S^S '-"6' 2«S ^9e^ <^T
-H
I in
1 H
•i '
192
AMONG THE MINES OF MEXICO
back while the horses were turned out to one side and
disconnected, all without stopping the hoisting.
There was no brake on any of these old malacates; when
it was desired to hold them at any given point, an at-
tachment was made to the nearest fixed timber.
Rawhide buckets, made by sewing together two
bulls' hides, were used exclusively. In these, both ore
and water were hoisted, and the experience of Ameri-
can engineers has proved that for taking water out of
shafts in sinkinr , the rawhide is better than anything
else, being lighcer and easier to handle in proportion
to the quantity of water raised than any other form
of bailer.
Over the shaft stands the shaky head-frame built
in 1872 during the unwatering of the mine by the
engineers of the Mexican company. They started
with four winches, not over 20 h.p. apiece, and fooled
along for nine years, finally getting the water out;
then, in 1881, they purchased a good Fraser &
Chalmers' double-drum double-cylinder winding en-
gine of 120 h.p. Mr. Dwight Furness, who was in
our party, told me that when he visited the mine in
1888, the yard was full of women engag-^d in sorting
ore. They sent 300 tons of this ore to the mills, the
remainder being shipped to Germany. These opera-
tions stopped in 1892, and the water has been rising
in the shaft ever since. I saw some of the little hoists
used in 1872; they had tooth-gearing made of mor-
tised wood; they came from Manchester, and were
:<-'sz>^^^i£^.^m'L
;r^?Ais" "■' •■ r^iL-iW^
l«o Views of the Tiro General. Old Head-Frame, Boiler House,
AND Chimneys
miw-
T^^'^^w:
i
'f- ii
'i
}.
H
■^.Sll:.
UNWATERING THE VALENCIANA
193
brought on ox-carts from Vera Cruz, a distance of
fully 500 miles.
A little farther north is the other great shaft, that
of Guadalupe, which is 22 feet in diameter, and 325
metres, or 1,072 feet deep. It has a hexagonal collar
built of masonry; through it a great deal of material
was hoisted, the dump being the largest on the Veta
Madre, containing 350,000 tons.
The unwatering of the Valenciana shaft must
have been a wonderful spectacle; the story of it is told
in the old company's records. When they began,
there were four steam-hoists raising as many iron
buckets restrained by wire guides. The water being
high in the shaft, it was not possible to anchor the
guides to the bottom, so they were attached to a big
wooden float, which was weighted until it sank.
Then the upper ends of the guide-ropes were run
over sheaves, in order that they might be paid out as
the water was lowered. As long as only one hoist
was running, all went finely ; but when all four got to
work, the apparatus, that is, the float, guide-ropes,
and toneles (bailing-buckets), commenced to twist
until the whole lot of them were completely ^vound
up in an utterly hopeless tangle. The bailing opera-
tions had removed the water unequally over the area
of the shaft, and this had created a vortex that caused
the float to move round, twisting the 16 ropes used
IS guides and the eight more employed in balance-
hoisting, until with rapidly increasing gyrations, the
.fe,.#
IN
till
V- l
'*■, ^f
il l:iF •
i V
* I
•i ^ i'i.
»94
AMONG THE MINES OF MEX )
float became the base of a tangle that baffled descrip-
tion and made the engineers hysterical.
After the unwatering was completed, in 1881,
Miguel Rul made a speech" before the Guanajuato
Societ ■ of Engineers, and in that speech he dwelt
upon their early troubles. The speech is on record.
He describes the cylindrical iron bailers, made of gal-
vanized sheets of No. 22 iron, with wooden bottoms
and rawhide valves ; he tells of the various difficulties
with the valve mechanism and over-winding, and then
1 e finally comes to the trouble connected with the
attachmei t for the eight wire-guides below the sur-
face of the water in the shaft. I quote his words:
"On making the general trial with the four bolsters,
after many partial trials which had resulted well, we
noticed a phenomenon which disconcerted us. The
effect of the different movements on the single timber-
frame, to which the guides were attached below
water-level, commenced to stir the water and to pro-
duce a tumultuous motion of rotation, which finished
by resembling a water-spout and winding up the
cables and guides, completely interrupting the ma-
ncBuvres. Many times we four engineers repeated the
trial through a whole day, and the following day with
only three (since he who recites this fell ill), withe it
obtaining any favorable result. The three com-
panions came to the bedside of the patient com-
pletely disheartened and sad, as was to be expected,
,. , "T'''5 speech, before the Guanajuato Society of Engineers, was pub-
lished m their Bulletin, and is dated August 5, 1888.
•fe!i"
EUREKA!
J95
but at the same instant the same exclamation burst
from the mouths of all, the very syllables falling to-
gether, without anyone of the four being able to say,
'I was the first to speak'; we shouted, 'We will tecure
the fixity of the frame with diagonal props resting against
the walls of the shaffl This common idea was the
equivalent of the Eureka! of the Greeks. It raised the
patient from his bed, re-established happiness and,
when put in operation, it gave the much desired re-
su't. The ninth day of June, 1873, the unwaterii:g
>vas inaugurated with great solemnity."
What a scene it must have been; the courtyard
fairly buzzing with the noise of the little hoists, the
shouts of the bewildered engineers, the imprecations
of the workmen, and the tremendous turmoil of the
water in the big shaft as the guide-ropes twisted into
a hopeless coil ! And then the silence when the whole
came to a futile conclusion, the operations remain-
ing suspended until those three mine captains, gath-
ered around the bed of their invalided comrade, were
suddenly inspired with the happy solution of their
trouble. The courtyard is empty now, the waters
have again invaded the shaft, and the vertical rays
of sunlight once more pierce the gloom within the
stagnant pit.
(tfyxpYzr 26
li
Ul
:Ar
THE MALACATE AND ITS OPERATION-THE AVIO
SYSTEM-ELECTRIC POWER— A CURIOUS DIFFI-
CULTY— HO^V THE EAGLES INTERRUPT THE CUR-
RENT — A - RIKE.
S a rule the miner does not
choose the top of a hill for the
site of his shaft; he goes where
he can economize on his sink-
ing, without depriving himself
of the chance to distribute the
waste rock. At Guanajuato the
shafts are on knolls, some of
which rise to the dignity of hills. The reason for
this was the space the Spanish miners wanted for
their malacates or horse-whims. At each shaft the re
were so many of these that a yard of 100-foot rad'us
was required. When this had been planned they - , . . ■
begin to construct a wall just beyond the end •
arms of the malacute, the wall being built with the w. ..
(extracted from the shaft), which was then filled 'nto
the enclosure until the yard had a level surface. The
haciendas were rarely near the mine, they were erected
in the town, for the sake of safety and convenience.
The ore was carried on mules to lue patio establish-
ments, which were custom mills.
I
I,.
"li'
UA
1
I
1
r
» ^ ■ !
!
t
't
■-.--. — — jL_: &_1 — I
tl'*
t f
*ff
Ir i
i
i'l.
-■?1
' a
1
i i
';f|
1 p
[J
1
^i
3
<
■;*fP^«ik'. '^
THE AVIO CONTRACTS
197
The mines were not worked by their owners but
by parties who secured a lease in perpetuii_, termed
an a'jio, which gave them (the aviadores) the right to
do wiiat they pleased in the mine, and to make con-
tracts for the disposal cf the ore. The aviadores
charged, as a lien against the mine, all expense of
whatever nature they incurred, such as development,
operation, taxes, plant — in fact, everything. Against
these items they credited the net returns obtained
from the sale of ore, but being able to dispose of it
wherever they pleased, they built haciendas on their
own account and then made numerous contracts for
the treatment of the ore, and mixed the several grades
of it so that the yield could not meet the treatment
charges. Then, as the owner never got a centavo
unless there was a balance to credit, he never received
anything. The mine ran up an ever-increasing debt
until it amounted to an impossible sum; thus, for ex-
ample, in the group of mines held by the Guanajuato
Reduction & Mines Company, the indebtedness
amounted to 6,000,000 pesos, most of this sum being
entered against four properties, namely, the Rayas,
Mellado, Cata, and Valenciana.
The American company bought the avio contracts
and the debt becomes payable to these new owners;
the company inherits all the old contracts, including
the agreement for ore-treatment- it will never have to
pay the former — almost nebulous — owners unless the
profits to the mine from sale of ore to reduction works
first repay the accumulated interest and then grow
r^
ii
)'■
I
I9t
AMONG THE MINES OF MEXICO
into a surplus. All the contracts are based on the old
treatment charge, which was: 360 grams silver per
ton to be deducted from contents of ore, the balance
to be paid for at the rate of 3 centavos per gram; and
the gold contents up to 6 grams per ton to be paid for
at the rate of 30 centavos per gram; between 6 and 15
grams, the payment to be 45 centavos. As the aver-
age ore of the best mines contains 350 to 400 grams
silver and 3 grams gold, it is pretty obvious that the
aviadores will not have to make an accounting. Several
attempts, naturally, have been made to break these
curious Spanish contracts, but in vain. The aviadores
are the unquestioned owners of the mines today and
no court can invalidate their peculiar rights.
The new enterprises at Guanajuato have ^wal-
lowed the avios, and all the big mines have passed out
of the hands of the native population. It is a fact that
the Mexicans look upon the American operations with
scepticism, largely because earlier efforts made by for-
eigners came to grief. They are inclined to regard
with humor the removal of dumps and the working of
abandoned mines; in consequence, although the old
work was done by their own people, only a few local
merchants have any financial interest in the present
profitable undertakings.
The introduction of electric power has been of
great help in the re-opening of the old mines at
Guanajuato. It used to cost 400 pesos per horse-
power per annum, burning oak for fuel and using
compound engines. Now the rate is five pesos per
.^,..:Ak,
{'—J ~jfT,
A Bit of Old Mexico
A Distant View ok GrAwirxTo
HK V'll.I.AS OK THK I'kK^A
k--^
INTRODUCTION OF ELECTRIC POWER 199
horse-power month for the right to use electricity,
and 0.026 centavos per kilowatt-hour, the latter be-
ing equal to about five pesos more per month if run-
ning steadily, making the cost 10 pesos per h. p.
month. The power comes from the falls of Zamora,
on the Duero river, in the State of Michoacan and
101 miles from Guanajuato. There 45,000 to 60,000
volts are generated, with a step-down to 15,000 volts
and again to 440 volts. Thus 4,0' '^' h.p. is generated,
and another plant of equal capacity is about to be
erected. Time flies. This must now be completed,
for I speak of more than a year ago (November,
1905), when I visited Guanajuato.
The natives were troublesome at first; they cut
and stole several hundred metres of copper wire.
Two men were killed by a live wire, after public warn-
ing of the danger. There was also some difficulty
at first in transmitting power, by reason of the sud-
den change in temperature at dawn, when there is a
rise of 15° C. This causes condensation of moisture
on the porcelain insulators, which remain cool after
the temperature of the surrounding air has risen. The
moisture on the insulators is sufficient to cause the
current to short-circuit between the iron pin of the
insulator and the cross-arm of the iron tower. This
happens between 5 and 6 a. m. The only way to stop
it is to turn off the current, so that there is a break
for an hour. However, energetic investigation into
the subject will solve this difficulty, a return to
wooden pins being possible. At first the break in
'il
7
1^1
200
AMONG THE MINES OF MEXICO
transmission was attributed to the malice of d's-
charged employees and then to the eagles, many of
which were found dead at the base of the towers.
They alight on the top of the iron supports at dawn
and stretch their wings so as to arc across the wires,
being killed instantly, but establishing a short-circuit
through themselves before they drop.
f^: '
' I m^f
'if ]
4
ilf
CbapUr27
THE PEREGRINA MINE— OLD SPANISH WORKINGS-
SHRINES UNDERGROUND — ACETYLENE LAMPS —
SAMPLING A DUMP.
N the Peregrina mine, near
Guanajuato, I had a good oppor-
tunity of examining some typi-
cal old Spanish-Mexican work-
ings. We entered by a door
into a small gallery and thence
through the opening or mouth
of the mine {boca de tnina) that
descended into the darkness. The way was down a
twisting stairway that zig-zagged within the vein-
walls ; the steps were laid in lime mortar, the general
slope varying between 45 and 56°. Such passages
are common in the old Mexican mines ; they are made
in stopes, the filling of which has been used to build
the masonry of the stairway. At intervals, shrines
are to be seen; there was one 30 feet from the en-
trance, just at the end of daylight, and there was a
principal shrine in a parapet above the big workings
{obra grande) at the 100-ft. level. Every shrine is
guarded by lighted candles, left there by the miners;
and it is said that they will even go up and down the
underground passages in the dark in order to save
candles for this purpose. At about 5 o'clock, when
i
aoa
AMONG THE MINES OF MEXICO
the shifts change, t.iere are ISO to 200 candles burning
before the principal shrine, forming a grand illumina-
tion, the effect of which is heightened by the cavern-
ous old stopes that yawn in front of the sacred image.
As they pass it, the men stop and make a genuflection,
with the sign of the cross. Descending farther, the
stairway becomes wider as it passes into the big stope
and we noticed another shrine — a toss set in a frame,
with a solitary candle; this marks the spot where a
man carrying drills {refaccthnero) tripped at the head
of a series of steps and fell fatally.
The big stope is a cavernous excavation 250 feet
long, by 450 feet deep, and 8 to 25 feet wide. The
footway at the end of the first stairs, about 100 feet
from daylight, is blasted in the wall of the lode and
is provided with a parapet of masonry. Leaning over
it, one looks into an abyss, the efifect being like a
miniature Cornice road underground. The lode is
nearly vertical, changing from 80° W, at the south
end of the mine, to a dip of 70° E, at the north end.
The ore is from 8 to 20 feet wide ; it consists of quartz,
partly ribboned and traversing a breccia, the edges
of which show replacement ; it follows a line of frac-
ture in the breccia; where the vein is tight and the
quartz massive, the silver is highest in proportion to
gold, ranging from 50 to 55%. Going south the lode
becomes more open, the vugs contain clay, and there
is such evidence of leaching as is usually seen close to
the surface. In this part of the mine the proportion
of silver to £,old is smaller. The Mexicans could not
m
1
1= -Vv ^
1
^^
<' HB MF
n
Shrink in thk Pkhm^rina Mine
II "!'
fi
f. :s
; I ■ i t
!
i 'i
I
Hacienda San Francisco de Pastita
Hit^^^BVh^^^^^m^
■ .^d^^^^H^r ^HP^^' ' ^"^^
^
!., *«-^. ■ — ^^ !
- ■^-. ^.:^:^^s.-/ r¥--:i!rr'!r-
i li
m^^^^^L^
:t.V -»«ff^ -..L^
ACETYLENE LAMPS
ao3
work the gold ore because the haciendas paid nothing
for gold and the ore- buyers gave only 30 centavos per
grai , when it is really worth 66 cents or 132 centavos
per gram. This ore cannot be sorted like that which
is rich in silver, the argentite being visible in threads
and spots, while the metallic gold is disseminated in
particles too small to be seen. The argentite some-
times impregnates the chalcedonic quartz so deli-
cately as to make a moss agate.
Our progress through the m:..e was lighted by
two peoncs carrying mechas or torches. Mr. E. P.
Ryan, the superintendent of the property, carrier' an
acetylene lamp, so that the old and the new were well
contrasted. The time may come when acetylene will
be in general use underground, but it will not become
popular until the present lamp is superseded by some-
thing better. As it is now, you have a small can that
holds the granulated calcium carbide and to this
water is added; then the cover is securely replaced,
and the chemical acti' n produces the acetylene gas,
which is lit as it escapes through a small aperture.
The smell of it gave me a headache, both in Mexico
and in the Lake Superior copper mines, the two dis-
tricts where I used acetylene lamps. But there is a
newer invention that promises to prevent the escape
of gas and the consequent headache. The emission
of gas is nicely regulated and all of it is burnt in the
process of illumination.
We met boys (tanateros) carrying waste in tanates,
the bags made of me fibre taken from the ixtle plant,
204
AMONG THE MINES OF MEXICO
m 1
I II
'I
tff
a variety of maguey. We were passed by other natives
descending to the place of their work, whistling as
they went at a trot down the rough steps." Then, in
contrast to such breathing antiquities, we found a
couple of young mining engineers" who were taking
samples in a thoroughly modern way, aided by Mexi-
can miners to do the moiling. The quartz ore was
hard and 10 to 15 feet wide, so that two moils were
blunted for each foot of sampling. They used the
straw hats of the barreteros to catch the sample. As
we proceeded, I coiild see by the white channeling
across the dark drifts that the work was being well
done.
Speaking of sampling, reminds me of the old
dumps and the way they were tested. At the Pere-
grina, this work was done by Mr. George A. Schroter.
He did it with system and care. An aggregate of
250 feet of shaft-sinking was required; one shaft was
as much as 70 feet deep, the usual depth being 40 feet.
Each shaft was 3 by 4 feet in the clear; it was kept
open by small timbers, 4 by 6 inches in cross-section.
Two-inch round oak spiling was driven over a 'bridge'
by double-hand hammers, as fast as the ground
yielded, in consequence of the removal of the material
at the bottom. The hoisting was done in baskets.
The average cost was $1.25 for the first metre and
then 25 cents extra for each succeeding metre of
"A Comishman thinks it unlucky to whistle when underground.
" G, A. Kennedy, of the Colorado School of Mines, and L. C. Pearce,
of the Michigan College of Mines.
I k
ii
V. n
i ^!
A Bin Stope in the Peregrina Mine
'a.4h kV_ (IT~~ 7*0^^^Kti. ^ 'A
> 5
iii
'■i^'d-^^Art'^'^.
BUYING OF ORE
ao5
sinking. The material obtained from each metre of
shaft was kept separate and sorted, for .25 centavos
per ton. This sorting was done by women, w ' > made
three piles, consisting respectively of fine ore, lump
(|uartz. and waste. On the day of my visit there
were 60 to "0 women at work, handling 100 to 110
tons per day. They are better than men — more
steady — because they do noi stop to smoke a ciga-
rette; nor do they steal as much as their husbands
and brothers. The sorting is done with a 3-lb. ham-
mer, a horn spoon, and a wicker basket (ckiquikuite)
reenforced with hide, holding about 30 pounds of ore.
The dump contained $8 to $9 per ton, 70% of this
assay-value being in gold. In the open-cut, where the
ore is mixed with wall-rock, the assays averaged about
$4.50 per ton. Underground, it was found that the
filling of old stopes ranged between $b and $10, being
highest in the southern part oi the mine, where the
ore is more difficult to sort.
The buying used to be done entirely at sight, the
grade and weight were both guessed, with plentiful
allowance for error and deception. The buscon or
tributer would make a pile and put big chunks of good
ore on the outside, and then fill his mouth with water
and squirt it over the pile, so as to make a fine show-
ing of black (silver) streaks across; the gray rock, on
the same principle as the old woman polished the ap-
ples for sale on her stall.
n
J\
w
I
(
' f
(i
w
^1
i
1 1 -
\
aSm
W i
ill h
■ I,
f'M !
y
ill
M
^\^Ux 25
THE DUMPS OF GUANAJUATO— HOW TO SA vfPLE—
THE MEXICAN IDEA — TWO TRUE STORIES — THE
BITER BIT.
HE dumps of Guanajuato have
figured largely in recv^nt pros-
pectuses, many companies hav-
ing been organized with the par-
ticular purpose of treating the
ore left by the old Mexican man-
agements. On careful inquiry,
I can give the average assay-
value of the best of these immense accumulations as
4 to 6 ounces of silver, and 1.5 grains of gold per ton,
equivalent to, say, $4 per ton.
When the American invasion began, the Mexi-
can was not slow to appreciate his opportunity. In
one case, peoncs were set to work removing the dump
in sacks and lording burros with it, so as to impress
a visitor with the idea that the stuflf was fairly rich.
But grab samples gave only five ounces of silver per
ton. It was hardly worth sacking!
As regards sampling, in all the discussions on
this subject while I was at Guanajuato, emphasis was
laid upon the danger of doing the work without trust-
worthy assistance. When using outside help, it is
TLi, ILiaiiVliM'.'^P
BiSKrvasii-
NATIVE IDEAS OF SAMPLING
207
difficult to prevent salting, if well planned, unless the
following three operations be performed:
1. Take samples with the help of the miners
available.
2. Blast the lode at a few points and take check
samples.
3. Cut down another set of samples yourself,
with the aid of the one personal assistant, without
whom such work should not be undertaken.
Mexican miners make poor assistants to an en-
gineer sampling a mine. When the groove is being
cut across the vein, they linger in the rich ore from
force of habit; it is hard to make them understand
that the poor quartz must be included. To this very
day, the Mexicans at Guanajuato deride the Ameri-
can method of sampling. One of our friends had
taken a large sample laboriously and carefully; he
was just in time to see the foreman of the mine in the
act of throwing out pieces of poor rock. "I'icne nada,"
"It carries nothing," he explained, as though it were
foolish to include anything but rich ore. Other en-
gineers can tell you of similr experiences, when,
after breaking a sample with particular care to make
it a true section of the vein, their Mexican helper has
picked out the barren-looking quartz. The whole
training of the native for generations has been to
sort his ore ♦"ejecting the poor stuff, and he cannot
get it into his head that anyone should do otherwise.
But he is not the only eccentric ; when I was in West-
ern Australia, during 1897, the owners of mining
Sf ~S I H I ' II III f'lP^I'
S.W.,', sri<itiMi't^
1-^
1 1
i
I
. I
Iw'-!'
)
1 \
I ii
It ^ I 41
2o8
AMONG THE MINES OF MEXICO
claims, or their representatives, did not hesitate to
express surprise at my omission to sample the small
patches of specimen ore. One incident I shall not for-
get, for I have a memento of it. Having been retained
to inspect a mine at Red Hill, near Coolgardie, I was
escorted to the spot — 50 miles away — by a Mr. Pat-
rick Walsh, a local celebrity of the boom days. His
language was picturesque and free, he had rudimen-
tary ideas of mining, and he took me for a 'tenderfoot'
— they call them 'new chums' in Australia. The mine
had several shafts and a couple of shallow adits, most
of which had but little ore to show, but on the top of
a small ridge there was a trench that exposed a quartz
cropping in which glistened a patch of beautiful
specimen ore — ounces of gold to the pound of quartz.
I admired it and proceeded to pass on, but he asked
me if I did not intend to take a sample, for in those
days pseudo-experts took a dozen samples of poor
quartz, and then a thirteenth unlucky one of speci-
men stuff, and averaged the lot, with the result that 4
dwt. ore appeared in their report as running 2 oz. 10
dwt., or something like it. Seeing that Mr. Walsh
would think I was not fair to his mine if I demurred,
the sample was taken. But it was never assayed; the
gold was melted, and I now possess a pair of hand-
some cuff-buttons to remind me of Red Hill, Western
Australia.
To return to Guanajuato; sampling of the streaky
lodes in that district is difficult; re-sampling of the
same groove is known to have given three such
MISLEADING SAMPLES
209
divergent results as 1,800, 350, and 150 grams of silver
per ton. The discrepancy is due in part to the fact
that the threads of argentite are thin and wavy in
direction, so that when the groove is made deeper by
a later cut, the amount of silver mineral obtained is
less or more, according to the chances of striking or
missing a streak or kilo of argentite. Re-sampling is
usually accompanied, in the case of an intelligent en-
gineer, by the special desire to avoid taking too much
of the rich stuff, and this is apt to cause a leaning the
contrary way. On the other hand, the first sampling
— made for the vendor — is likely to be left to the
Mexicans, who instinctively put too much of the soft
argentite into the hat that holds the ore as it is broken.
The story is told of a mine that, along its main
level, showed a width of 8 to 10 feet of beautiful
quartz ribboned with black threads of rich mineral.
The back of the drift looked handsome. An option
was secured by Americans residing at Guanajuato,
who knew rich ore when they saw it. The sampling
done by an engineer in behalf of a putative purchaser
gave the astonishingly low result of an average of $2
per ton. A protest against this finding ended in the
breaking of a few tons of ore with a view to checking
the sampling, and the result was 5 cents per ton less.
The black streaks were not argentite, but stibnite!
There was another story of an ore-purchasing
agent who found that the smelter returns at Monter-
rey were 307c less than his own sampling, on which he
had made settlements with the Mexicans. He dis-
i i
nwi
V 'i\
I 'if
I i'
210
AMONG THE MINES OF MEXICO
' t
covered that the ore, when being sampled at the mine,
was turned over in the teeth of a wind, which blew the
fine black (silver) dust over the fraction representing
the pulp that went to the assayer. This residual por-
tion was always placed to leeward. He lost 8,000
pesos, but took his medicine like a sportsman. In the
course of time, it was decided to sample at the receiv-
ing station instead of at the mine; there was a nice
yard (patio) available for the purpose, it was paved
with red brick of the usual soft character. The
buscones (tributers, or lessees of the mine) sent a f jp-
resentative to watch the sampling in their interest,
and he noticed that the sweeping of the floor threw red
brick-dust into the sample. He became fussy, and
insisted that the objectionable material should be
ejected, and it was. The ore-buyers' agent did not
prove obdurate, for the brick-dust included fine parti-
cles of rich ore that filtered to the bottom, making a
mixture 15% richer than the average. The 8,000
pesos that had been lost were soon recovered, and a
few more to make them comfortable.
'li
W' in', !:
i
(Tljapter 29
THE GEOLOGY OF THE VETA MADRE— A BIG FAULT
-POSITION OF THE OREBODIES— A CROSS-SECTION
-HUMBOLDT'S DESCRIPTION— WHAT IS A TRUE
\'EI\ ?
OME idea of the general geol-
ogy of the Guanajuato district
is obtainable along the road
that crosses La Bufa. I went
this way to the Peregrina mine,
seven miles from the city of
(iuanajuato, and incidentally
formed my first notions con-
cerning the country enclosing the Veta Madre.
The accompanying cross-section (Fig. 18) I owe
to Senor Ponciano Aguilar, of the Mexican Geologi-
cal Survey. It illustrates the fact that the Veta
Madre follows a fault of big throw, so that the foot-
wall is shale" and the hangfnf a series of layers of
volcanic fragmentary material. The magnitude of
the fault that made the Veta Madre is clearly
indicated.
In the shale of Guanajuato were detected the
first Triassic marine fossils found in Mexico. They
were bivalves, not well defined. The shale is meta-
* The Mexican geologists use the term 'schist' for this rock, but it is
a misnomer.
212
AMONG THE MINES OF MEXICO
T'
'ij
! •.
i t- ^
I »!.
ii
'li-'
I '
1!-
1i
, Hl'i'
tl 111 I '
I • li
Mir
J'f|i\j! i
hi t . fk i
W:
■I
g
(! 5
GEOLOGY OF THE VETA MADRE
213
morphic and resembles the Upper Trias of Zacatecas,
where fossil remnants of the same kind are found.
The Miocene agglomerate of the hanging wall,
usually called the 'red conglomerate,' or Guanajuato
formation, is overlaid by breccia and rhyolite tuff,
termed 'sandstone' by the ouitlanders, while the Mexi-
can geologists call it lozas". Next comes more ag-
glomerate and then tuff, the latter a succession of
layers of volcanic fragmentary material, altogether
Fig. 19.
1,200 feet thick, and reminding me of the formation
that prevails in the San Juan region of Colorado. On
"Lozas literally means flagstones, it is a term applied to the water-
laid volcanic dust, porous in texture and well stratified, which looks like
a sandstone. It lies on the top of the 'red conglo.-nerate' and below the
other tuffs. The lozas constitute a thinly bedded formation of green rocks,
only from 10 to 40 ft. thick. At some places the texture is fine enough
to make them equivalent to a 'free-stone,' eminently suitable for building
purposes. The facade of the Juarez theatre is built of this material, and
tlie ornamental stone-work all over Guanajuato is derived from this
source.
m
u
5 i
I I
* ■ I:
if . • i ■ i if
214
AMONG THE MINES OF MEXICO
the farther edges of the eruptive centre these clastic
rocks are replaced by lava flows of dense rhyolite.
The foot-wall of the big lode, as seen in this section,
is Miocene agglomerate, and different from the foot-
wall rocks north of the Sirena mine; the change of
formation being due to a cross-fault coming into the
Veta Madre on its foot-wall side, producing a down-
throw of the southern portion of the foot-wall rocks.
This is illustrated in the accompanying drawing (Fig.
19), made from a sketch given to me by Mr. R. H.
Burrows, an experienced economic geologist, resi-
dent at Guanajuato. The Sirena mine is indicated at
J; at B, the approximate relative position of the Va-
lenciana mine, the throw is at least 6,000 feet, while at
C, the place of the Cedro mine, the throw is probably
2,000 feet. The difference in throw is not effected
by bending of either side of the Veta Madre, but by
step-faults.
Northwest of this cross-fault it is difficult to de-
termine the extent of the displacement along the
Veta Madre, because the relation of the agglomerate
.^ the shale has not been established. After the lode
passes southeast of the cross-fault, the throw can
be determined by estimating the distance from the
top of the red agglomerate on the hanging-wall side
to the top of the same formation on the foot-wall side.
This distance is shown in the section B B, in Fig. 20,
where it is represented as 2,000 feet. Referring to the
section C C, there is no formation now in contact
above or below the shale, and the bottom of the red
f i i
SECTIONS OF THE VETA MADRE
215
4KCAS.
Etctto-n. BE.
Fig. 20. Plan and Sections of the Veta Madre.
After R. H. Burrows.
i
i'. I
■t (it: J 'I
i f
i ' I M
4 i ':S
i. ■
2l6
AMONG THE MINES OF MEXICO
agglomerate is nowhere visible. As the shale is old'r
than the red agglomerate, the throw will Le repre-
sented by the known thickness of the red beds, plus
the amount of the latter that has been eroded on the
foot-wall side of the lode. Of these two factors,
which together make up the sum of the throw, only
the first mentioned is definitely known. Starting
downward from the top of the red agglomerate on
Sirena Mtn. this formation is traced all the way to
Marfil, a distance of six miles, exhibiting a constint
strike and a dip varying from 5 to 30° east. The
thickness thus represented is fully ^.000 feet, so that,
omitting the other factor, it is well within the mark
to estimate the throw at 6,000 feet.
At the Sirena mine, the foot-wall is shale (prob-
ably Cretaceous), varying from argillaceous to cal-
careous, from clay to lime. On the hanging the lay-
ers of agglomerate dip eastward toward the lode.
The agglomerate becomes deeper as one goes south-
east r ' g the outcrop of the Veta Uadre; it feathers
out u, lothing at the Valenciana, and at Bustos it is
about 200 feet below the bottom of the valley. The
slope taken at right angles to the strike of the Veta
Madre, is about 30° downward and toward the vein,
the strata therefore making an angle of approxi-
mately 75° with the dip of the Mother Vein. The dip
of all the bedded rocks in the district is about due
east-west, and the strike of the lode is northwest-
southeast. It is not a simple vein, but a vein-system
within a zone 50 to 600 ft. wide. The principal ore-
?k-^l^
THE SIRENA OREBODY
317
bodies in the Sirena mine occur near the intersection
of the Amparo vein coming in from the hanging wall.
Much the same is true of the orebody in the Rayas
mine, formed at the intersection with the Santa
Toribio vein, which also comes into the main lode
from the hanging-wall side, the ore pitching with the
line of this intersection.
At the time of my visit, the Sirena was in bo-
nanza; a new orebody had been found on the fourth
level in a raise, where it touched the quartz of the old
foot-wall stopes. At the fifth level — 800 feet (on the
dip of the vein) below the Purisima adit and 1,320 feet
from the outcrop — cross-cuts and raises had proved
that there was 120 feet of pay-ore, which, allowing
for the diagonal course of the cross-cut and the dip
of the lode, was equivalent to a width of 65 feet. An-
other cross-cut, 300 feet farther east, had proved a
width » 45 feet. One section showed three ore-
streaks, parallel in strike, but converging in dip to-
ward the foot-wall.
In Fig. 21 I have drawn a generalized cross-sec-
tion of the Veta Madre as it appeared to me on the
fifth level of the Sirena mine. J J is the hanging wall
and C C is the foot-wall; B B 's the lower limit of the
main vein and is called the / crmedio, or intermediate
wall. The distance between J and B is 25 to 75 feet,
between B and C, 75 to 150 feet. On the foot- wall
there is a vein, from 1 to 6 feet wide, of quartz, which
is not ore. The shale is bent near the foot-wall and is
shattered between that line and the intermedio. B B
2l8
AMONG THE MINES OF MEXICO
represents the line of the fault along which a width
of shattered rock has created an ore-channel. Be-
tween /) and A there are numerous stringers of quartz.
•S-^:.'"'-~^>---
/
r~l'"« [iC>.,.., i.»u r^jj,.!.
IM.;, 21.
some of which is ore, but the main orehody extends
from the hanging into the agglomerate. The so-
called 'foot-wall quartz' has been stoped on the fourth
level for a width of 20 feet, and on the higher levels
LIMITS OF PAY-ORE
219
this body o: poor quartz is 200 feet wide and there it
lies aj^ainst the shale. The lode is broken by step-
faults east of the Principe shaft, the fault-planes pitch-
in,tr east at a strong angle. For a distance of 1,200
feet on the vein, northwestward from the Principe
shaft, the lode is ore-bearing, to a varying extent, and
in bodies of different shape. The pay-ore lies in soft
iirccciated ground, exhibiting traces of oxidation and
lying between the hard vein-quartz of the foot-wall
and mineralized ground, the limit of which has not
been determined. It is an imi regnation of irregular
shape, extending along the structural lines of the ag-
glomerate. At the time of my visit the ore as sent
to the mill yielded 517 grams of silver and 2.76 gm.
jjold per ton. The agglomerate does not wholly lose
its identity by reason of impregnation with ore, and
it is necessary to sample carefully in order to deter-
mine where profitable exploitation will cease. It is
fair to say that the cyanide process has done more to
widen pay-ore than the geologist, that is to '^i% , che
decrease in the cost of milling has enabled the man-
ag^cr to treat profitably material previously considered
too poor. Where the lode is not rich the distinction
between quartzified country and profitable ore is de-
termined by the assayer, and not by the mineralogist.
The stalactites of iron on timbers and on the foot-
wall of the old workings carry silver. As much as
30 grair.s, say, an ounce of silver, has been detected in
such deposits formed within one year. The general
assay-value is 5 to 20 grams per ton. After rains the
111
t^
'I-,
,1;
!
I. I
I . V:
U^i
220
AMONG THE MIXES OF MEXICO
water of the mine contains 2>^ to 3% sulphuric acid
and it will eat through an iron pipe %-inch thick
within 60 days.
I was informed that the orebody of the hanging
wall, in the Sirena mine, was found while blasting for
a cross-cut, intended to make room for a new hoist
underground. The appearance of this ore suggests
that it was formed by one of those movements that
took place subsequent to the formation of the main
fracture of the Veta Madre and its accompanying
vein-matter; this later movement evidently shat-
tered the older quartz-filling and then passed through
the hanging-wall country so as to make a big mass
of brecciated ground, suitable for infiltration by min-
eral solutions, which re-cemented it with calcite and
the more valuable metallic minerals. Diamond-
drilling ought to be useful in exploring this ground;
for the orebodies are large, but not connected. The
old stairways and communicating passages appear
often to be the bottom of underhand stopes, and
therefore suggest the lower limit of profitable ore at
the time the work was done.
The accompanyint,^ photograph illustrates a part
of the Veta Madre as seen in the Rayas mine. It is
near the foot-wall, as indicated by the fragments of
shale, which are partly silicified at the edges. Black
threads of argentite traverse the white quartz.
The geology of the Veta Madre has not received
detailed study as yet, at least nothing has been pub-
lished commensurate with the size of the subject, so
i «l
(»
m
l\
''^
-n '
■ 1 m
■
Jt 4 i
1;
NOTES FROM HUMBOLDT
221
that Humboldt's observations still possess a com-
manding interest. I shall quote from the old English
translation already mentioned. He says: "The fa-
mous vt.. .f Guanaxuato, which has alone, since the
end of the sixteenth century, produced a mass of sil-
ver equal to fourteen hundred millions of francs,'"
crosses the southern slope of the Sierra de Santa
Rosa." Beginning to touch upon geological matters,
he states that "the most ancient rock known in the
district is the clay slate {thonschiefer) which reposes
on the granite rock of Zacatecas. It is of an ash-gray
color and is frequently intersected by an infinity of
small quartz veins. I consider this clay slate as a
primitive formation, although the beds with very thin
folia and which are surcharged with carbon, appear
to approximate a transition clay slate. These beds
{hoja de libra) are for the most part near the surface.
On digging the great pit (tiro general) of Valenciana,
they discovered banks of syenite or hornblende schist
and .:ue serpentine, alternating with one another and
forming subordinate beds in the clay slate."
Humboldt wrote in French, so that his use of the
term thonschiefer indicates that he was thinking of the
Erzgebirge, at that time— just one hundred years
ago — the most scientific mining centre in Europe.
His description of the shale, which constitutes the
foot-wall of the Veta Madre, is correct. It does ex-
hibit a ramification of quartz veins. But the label
• £57,754,620 or, say. $285,500,000.
222
AMONG THE MINES OF MEXICO
n!
'primitive' will not do, for the formation is pr |y
Cretaceous ; moreover, 'primitive' is a word be ng
to an outworn idea, that the basement rocks were the
origmal cooled crust of the earth. Petrography
knows no simple starting point; the rocks we see are
only m a particular stage out of the many through
which they pass in the course of their geological evo-
lution. The modern geologist begins with the old
crystallines, earlier than fossils. The undermost rock
now known is a granitic batholith, which seems in
places to have invaded the oldest schists. This granite
may be an original ign.-ous rock for aught we know.
It IS probably not a fused sediment, and is the nearest
approach to anything 'primitive.' The crystalline
granite, formed by slow cooling from a molten
magma, when exposed to weathering at the surface of
the earth, becomes disintegrated into sand and clay
which, being deposited in the ocean depths, are re-
cemented and again solidified in ' rocess of time, pas<:-
mg through chemical and physical changes that make
sandstone out of the sand, and shale out of the clay,
at first, and then by further interplay of subterranean
pressure, heat, and chemical action, these become on
the one hand quartzite, on the other slate, with a
mixed product of schist between them.
The Valenciana shaft passes through the car-
bonaceous shale, with layers like the leaves of a book
(hoja de libro) and penetrates the intrusive diorite, the
decomposition of which, in places, gives the magne-
sian rock that Humboldt called 'serpentine.' He con-
'\mi 1
^ja^maE^B^snisM^sssaKr?f!sm^ssj^^K'Tmm^KStT'-MM7^m^F?^
PORPHYRY AND FREE-STONE 223
tinues: "Porphyry forms gigantic stony masses which
appear at a distance under the strangest aspect, fre-
quently hke ruins of walls and bastions. In the coun
try they go by the name of buffa. This porphyry, of
which the Sierra de Santa Rosa is chiefly composed,
IS generally of a greenish color." Colors in rocks
have ceased to have the importance they once had for
we have learned that the same rock can change its
appearance while retaining an identitv of compo-
sition. The name bufa still lingers at' Guanajuato
(but It IS spelled with one f). and has almost replaced
the higher sounding 'Sierra de Santa Rosa ' The
sculptured summits and bold cliffs of La Bufa are
due to unequal weathering of the rhyolite tuff that
caps the Guanajuato series. Even in those days the
term porphyry' played many parts.
Continuing, Von Humboldt mentions that "on
the southern slope of the Sierra, the clay slate is cov-
ered with free-stone of very old formation. This free-
stone {urfels-conglomcrat) is a breccia of clayey cement
mixed with oxide of iron, in which are imbedded
angulous fragments of quartz, lydian stone, syenite
porphyry, and splintery hornstone." He speaks of
the dip being opposed to that of the clay slate. Above
this free-stone' there is "an agglomeration {lozero) of
ater date from which the finest hewn stone is manu-
factured.
The free-stone is a fine-grained tuff, used in the
building of the city of Guanajuato, as already men-
tioned; It IS soft enough to be easily worked, and yet
' t4i:-:^'m^itS(.Mi>Ai. ;
lI ''
m
z ■,»,
2-4
AMONG THE MINES OF MEXICO
hardens on weathering, so as to be durable. It is the
cantcra of the Mexicans. This formation occurs both
above the shale of the foot-wall country, as Humboldt
states, and also on the hanging-wall side; in fact, it
marks the extent of the great fault of 1,200 feet, along
which the Veta Madre was made. On the hanging-
wall side the dip of the country is nearly at right
angles to the vein, which cuts strongly across the
bedding, and, for a great distance, follows a line along
which the later tufifs and breccia are opposed to the
shale. But on the outer edges of the mining district,
the vein cuts through the younger rocks also. Hum-
boldt saw this; he says: "The vein traverses both the
clay slate and porphyry. We have already stated that
it has been wrought for a length of more than 12,000
metres ; and ye*: the enormous mass of silver which it
has supplied for the last hundred years, sufficient of
itself to produce a change in the price of commodities
in Europe," has been extracted from that part of the
vein alone contained between the pits of Esperanza
and Santa Anita, an extent of less than 2,600 metres
(8,529 ft.). In this part we find the mines of Valen-
ciana, Cata, San Lorenzo, Animas, Mellado, Frau-
stros, Rayas, and Santa Anita, which at different
periods have been very highly celebrated."
According to Humboldt, the European miners
had been in doubt whether to consider the Veta
Madre a "true vein" or a "metalliferous bed
" An effect produced seventy years later, by the equally tremendous
output from the Comstock lode, in Nevada.
WHAT IS A TRUE VEIN ?
225
(crzlager)." He then proceeds to give some sound geo-
logical views:
"If we examine only the veta madre of Guanaxuato
where the roof and the wall, in the mines of the Vclen-
ciana or Rayas, are of clay slate, we might oe tempted
to acquiesce -.1 the latter opinion; for far from cutting
or crossing the strata of the rock, the vein has exactly
the same direction and the same inclination as its
strata; but can a metalliferous bed which has been
formed at the same period as the whole mass of the
mountain in which it is found, pass from a superior
to an inferior rock, from porph)'ry to clay slate? If
the veta madre was really a bed, we should not find
angular fragments of its roof contained in its mass,
as we generally observe on points where the roof is
a slate charged with carbone, and the wall a talc slate.
In a vein, the roof and the wall are deemed anterior
to the formation of the crevice, and to the minerals
which have successfully filled it; but a bed has un-
doubtedly pre-existed to the strata of the rock which
compose its roof. Hence we may discover in a bed
fragment:^ of the wall, but never pieces detached from
the roof."
The attempts to define a 'true vein' have not
ceased even a hundred years after the above words
were written. While the debate is adjourned and re-
sumed at intervals by savants, the miner has disre-
garded evasive distinctions and has proved by his
profitable toil that "metalliferous beds" are just about
as good as the "true veins." The Calumet & Hecla,
226
AMONG THE MINES OF MEXICO
I
5 li'Sl-
the Leadville orebodies, the Aspen contacts, the ad-
dle reefs of Bendigo and Broken Hill, the 1 nticular
masses of Rio Tinto, the disseminated copper de-
posits of Binghan: and Ely — to mention only a few —
are representative of occurrences that do not belong
I to what the schools of Saxony and Cornwall labeled
'true fissure veins.' Nevertheless, Humboldt's effort
to distinguish betwen an ore deposit contempora-
neous with the formation that encloses it, and one
that has originated along later fractures crossing such
rocks, is no* without interest. He refers to the in-
clusion of rock fragments in the Veta Madre thus:
"Its exte 1* varies like that of all the veins of
Europe. When not ramified, it is generally from
12 to 15 metres in breadth; sometimes it is even
strangled to the extent of half a metre; and it is for
the most part found divided into three masses
(cuerpos), separated either by banks of rock {caballos)
or by parts of the gangue almost destitute of minerals.
In the mine of Valenciana the Veta Madre has been
found without ramification, and f >r a breadth of
seven metres, from the surface of the ground to the
depth of 170 metres. At this point it divides into
three branches, and its extent, reckoning from the
walls to the roof of the entire mass, is 50 and some-
times even 60 metres. Of these three branches of
the vein there is in general but one alone which is
rich; and sometimes when all the three join and drag
one another, as at Valenciana, near the pit of San
Antonio, at a depth of 300 metres, the vein contains
I J
MEXICAN MINING TERMS
M7
immense riches of an extent (puissance) of more than
25 metres. * * * Valenciana is almost the sole
example of a mine, which for forty years has never
yielded less to its proprietors than from two to three
million of francs (£82,506 to £123,759) of annual
profit."
Here wc have the Spanish equivalent of our term
'horse' literally translated into caballo; it is the in-
cluded rock that the vein rides, passing astride of it.
If the branches of the vein do not re-unite, the result
is a split or embranchment; if they come together, it
is a 'horse.'
Mexican mining terms are frequently dis-
tinguished by their aptitude. The hanging wall is
called alto (high or up), the foot-wall is bajo (down
or low). But at El Oro I found that the natives
spoke of the hanging as reliz (pronounced like re-
lease). It is a word signifying a landslide or slip,
and as suggesting a plane of parting or what a miner
calls a '.shooting course,' it struck me as excellent.
The hanging is also described as reliz arriba, or arriba
by itself. Waste is lepclate. All stringers are called
hilos, kilo being a thread. Ore that is speckled with
black sulphide is known as mosceado, or fly-specked,
mosca being a fly. At Guanajuato the honeycombed
quartz on the foot-wall of the Feta Madre is termed
chcrasco.
Dikes of andesite penetrate the agglomerate and
the shale in various directions, and, as Mr. Robert T.
Hill suggests, it is to them that we may impute the
228
AMONG THE MINES OF MEXICO
latest mineralization of the district; at least, it is
probable that their intrusion along lines of fracture
was coincident with a period of thermal activity.
The Veta Madre, being essentially a big width of
rock sheeted by fractures near the contact of two
unlike formations, afforded unusually favorable con-
ditions for the penetration of ore-forming solutions,
which followed the main fractures and spread out-
ward and upward into the shattered agglomerate,
where they found the inducement to precipitate the
wealth of silver that is now suggested by the name
of Guanajuato.
\i
' >
' • W
i I I'M.
■ m
M
ui
■m^m*?^'
TlIK i AN
On thk Strket
(ri)apUr 30
THE DEVFXOPMENT OF METALLURGICAL PRAC-
TICE AT THE SIRENA MILL— FROM AMALGAMATION
TO CYANIDATION— RE-GRINDING.
T is worth while to tell the story
n't the metallurgical develop-
ment at the Sirena mill, more
properly named La Hacienda San
Francisco de Pastita. The suc-
cessor to the old patio was a mill
erected ir . ^^\ it contained 20
stamps, ». weighing 1,250
pounds. The ore was first broken by a 9 by 15-in,
Blake crusher and was then reduced to 20 mesh by
the stamps, from which it was passed to six Boss
rapid-grinding pans. Here it was re-ground, so that
all .-.ave 5 to 107'^ passed an 80-mesh screen; and then
it descended to 12 more pans and six settlers. From
these the pu!,) went to five Wilfley tables. The
capacity of the mill was 1,500 to 1,800 tons per month.
The product was amalgam and concentrate.
The pans extracted 657c of the assay-value and
the concentrate contained 127o more. This was on
the oxidized ore. Although the concentrate con-
tained two kilograms or 64.2 ounces of silver, it
barely paid to send it to market under the smelter
conditions then existing in that part of Mexico.
2y>
AMONG THE MINES OF MEXICO
im
However, another factor came into play; as the lower
workings were opened up, the percentage of recovery
by amalgamation fell off until it was only 607c. Con-
currently, the consumption of mercury and copper
sulphate in the pans increased, while the concentrate
became richer— 5 to 7 kg. silver per ton. The method
was changed ; concentration was made to precede pan
amalgamation.
By this new arrangement, the cost of milling
was reduced from 7.86 pesos to 4.81. The concentra-
tion was carried further, so that the product con-
tained 10 to 11 kg. silver and 115 gm. gold per ton;
yet the weight of concentrate remained at 2 per cent
of the crude ore. The higher recovery by concentra-
tion balanced the lower yield by amalgamation, the
commercial result being less satisfactory because the
precious metals in the form of amalgam were worth
more than when enclosed within a concentrate that
had to be transported to a distant smelter. More-
over, the variation in smelter rates introduced a
factor of uncertainty.
Extraction finally fell below 60%. This sug-
gested an enlargement of the mill, so as to lower the
fixed charges. At this period the Government tax
and the expenses in connection with realization of
bullion amounted to 11% of its gross value. The
poor extraction and the high imposts left but a small
margin of profit. A search for better metallurgical
treatment was undertaken. The cyanidation tests
made by Leonard Holms in 1901 did not seem to
si
'-'vm. A'
¥A-i'^^*i^ :^^^&::^}f^', .^. .. -^^ ' ^ . . 'i^mr^%- .. ■<wiiii ' . ki^'
CONCENTRATION AND AMALGAMATION
231
justify turning to that method at that time; subse-
quently, however, E. M. Hamilton made a new re-
search on a working basis, with a 5-ton plant, and he
obtained encouraging results. However, nothing
was done for a year.
Meanwhile the recovery by amalgamation con-
tinued to dwindle and when cyanidation was re-com-
menced, there was a fear lest the further change in
the ore with depth might affect extraction by
cyanide as it had done that by mercury. In 1904,
Bernard MacDonald was engaged to investigate the
problem, with the idea, among others, that the
Hendryx process might be applied. Complete cya-
nide tests were made and every kind of ore in the mine
was tried. The results fully confirmed Hamilton's
earlier work, even on the ore from the bottom of the
Sirena mine. It was demonstrated that finer grind-
ing was required and that even the concentrate, if
ground dry to pass through 200 mesh, would yield
94 to 967o with the use of a 2.5% cyanide solution — a
solution unusually strong, but based upon the rela-
tive proportion of silver to be dissolved. A weaker
solution would have done better, as was proved
later.
In these tests, a fresh solution was introduced
each 24 hours into bottles that were agitated by
being attached to the periphery of a slowly revolving
wheel. This failed to reproduce working conditions,
because it eliminated a drawback inevitable in prac-
tice — that is, foul solutions. For this reason the
232
AMONG THE MINES OF MEXICO
results were higher than was to be expected in the
mill, but they warranted the belief that a plant spe-
cially designed for the treatment of the concentrate
would yield larger profits than the sale of the concen-
trate to the smelters. The tests demonstrated also
that the silver sulphide was readily attacked by cy-
anide when the grinding was as fine as 200 mesh. As
yet, no plant has been erected to treat the concentrate,
but it is likely that this will be done.
In the meanwhile — this was in April, 1904 — it
was decided to erect the existing cyanide plant, which
started to work in May, 1905. When concentration
was made to precede amalgamation, the grinding in
pans was discontinued, it being found that amal-
gamation was more effective in charges than as a
continuous process. In erecting the cyanide annex,
the only change required was to divert the flow from
the Wilfley tables to cone-classifiers. The coarse
sand went to a tube-mill of Allis-Chalmers make, 5
ft. diam. and 22 ft. long. It was lined with chilled
iron, which, after a three weeks' run, collapsed, so
that the use of the tube stopped abruptly. It has
not been employed since. Tests proved that the
benefit of the re-grinding in the tube hardly war-
ranted the extra expense of repairs and power. The
first cone-classifiers were discarded, the p going
from the Wilfleys to a set of cone-' s that
separate the sand from the slime. Th' ,igement
is shown herewith, in Fig. 22, .^ is ; . je spitz-
kasten, 8 ft. wide and 8 ft. deep, the classification
v:^
U' <! i
Ik
THE PASTITA MILL
233
V <■
being by gravity. The sand, plus some slime, flows
through rubber goose-necks to a height two feet
above the bottom into four smaller cones or spitz-
lutten, 4 ft. wide and 4 ft. deep, equipped with
hydraulic jets. The undersize from all five cones
o
Q o
o
Fig. 22. Arsangement of Classifiers.
unites and flows to eight Callow steel settling-cones,
8 ft. diam. and 8 ft. deep, where it is de-watered.
Thence the pulp passes to three masonry vats, where
lime is added to effect settling previous to decanta-
tion, and at the same time destroying the acidity of
' ffi
k-
1
\l
I
h
^^H
51
' y^^c
"M
^m
>:;
' hk
/ .
i
''^^1
\:
|i^^H
ii
I 'ffl^l
t ;
I .,^9
j
^H
?!
■
-!
,1
H
-3»?^a'^-*^W»-
234
AMONG THE MINES OF MEXICO
K
the slime and bringing the positive alkalinity up to
\y2 pounds of lime per ton. Then this slime is
pumped to the treatment-vats, the sand meanwhile
going to collecting-vats, from which, after draining,
it is taken in cars to the treatment-vats.
This was the scheme at the commencement of
cyanidation; subsequently, the masonry vats, for-
merly employed in de-watering the pulp previous to
pan amalgamation, were modified so as to serve for
holding and thickening the slime. The five cone-
classifiers were moved into the stamp-mill, in order
not to lose 5^rade, and in this new position they de-
livered direct into the masonry vats behind the old
amalgamation pans, the vats built in the cyanide
annex being used for the same purpose, namely, to
de-water the slime. Even now it contains 70%
water, and this 70% is just so much liquid that has to
be displaced by the effective cyanide solution, until
perfect diffusion is attained.
The ore goes from the Sirena mine to the mill
in cars (Kilburn & Jacobs) of 50 cu. ft. capacity,
carrying 2.4 tons each. They have a double side-
dump, with gable bottom, and appear to work easily.
Waste is removed by sorting in the big courtyard at
the entrance of the main adit. A sorting belt is to
be used at the new Soledad shaft, the waste thus
eliminated being returned into the mine as filling.
The belt is to be 50 feet long, giving room for five
men on each side, and it will be illuminated by shaded
electric lights like a billiard table. Each man is to
TCW^^^T'^W^WT
^a
:tl
HANDLING OF ORE
235
sit astride a wooden horse, which is high enough to
giv freedom of reach over the belt.
Gold can be seen in the surface ores of the Sirena
mine; it accompanies the argentite. Pyrite does not
appear to be indicative, nor is it a close associate of
the precious metals; it is more plentiful in the un-
digested country rock. In the ore of the Peregrina
mine there is a little arsenical pyrite and also traces
of antimonial silver minerals. At Guanajuato gen-
erally, the average yield of concentrate does not ex-
ceed two per cent, carrying 150 to 1,600 oz. silver,
and from 1 to 30 oz. gold per ton, so that the problem
is to treat a small quantity of high-grade material in
competition with the excessive freight-charges of the
railroads and the heavy treatment-rates of the
smelters. Further, the Government tax is one per
cent less on bullion than it is on the precious metals
when in the form of concentrate.
In September, 1905, the mill treated 3,887 tons of
ore, containing 517 grams of silver and 2.76 grams
of gold per ton. On leaving the concentrators the
pulp assayed 302.5 gm. silver and 1.46 gm. gold.
The concentrate recovered amounted to 106 tons,
averaging 948.06 gm. silver and 46.92 gm. gold. The
cost of crushing and concentration amounted to 1.75
pesos per ton. The extraction by concentration was
50.1% of the silver and 49.1% of the gold.
The practice is still in course of developnicnt and
experiments are continually being made. Re-grind-
ing does not seem required by the Sirena ore; it is
i
I til
.'i-^vi-^>i'^fy*. -V
236
AMONG TI^E MINES OF MEXICO
stamped through ;. diagr^nal slot screen equivalent to
40 mesh; a cliuckbiock is used. Of the resulting
pulp, 80% goes through 100 mesh. The granular
quartz, when crushed, readily liberates the silver
sulphide, but the chalcedonic gangue in which the
silver occurs (in a cloudy dissemination like moss-
agate) needs fine grinding — all of it — to pass at least
100 mesh. The concentrate carries 30% silica; the
portion that passes through 200 mesh represents
15.5% by weight and as it is worth 398 pesos per ton,
it contains 427c of the assay-value of the ore.
In watching the agitation in the slime-vats, it
was noticeable how the circular motion becomes ac-
celerated until the moving mass of pulp and solution
advances faster than the paddles. On starting the
agitation, one can see the sinuous streaks of clear
cyanide solution in the slime, and this condition of
imperfect dispersion is never wholly overcome; it
is due to the resistance of slime to diffusion. I
noticed this appearance (or phenomenon) in a vat
that had been at work for 40 minutes. Another note;
even ten minutes after the agitator is stopped, the
movement of water a top of the vat continues in the
direction started by the paddles. Two pounds of
lime are added per ton of solution in order to hasten
settlement of the slime. The effects produced have
been discussed in connection with milling at El Oro.
The loss of sodium cyanide at the Sirena mill is
4.12 pounds per ton of crude ore, while the consump-
tion of lime is at the rate of 6 pounds, worth 12 pesos
■iz-'^tev.
ii^'fSmnf"
I
V
I
I M
2
}
i.-
[f
•
t. ? '
m
"I
-. - ^f
~
^^^
«--.- •
1
fe-^
•^
' ~ "
r
"^'
^ "^ Iv-i^
. . -'
u
O
3
Bl
S
H
S
<
a
3
O
to.
O
u
a.
S
O
TREATMENT IN THE VATS
237
per metric ton. Sodium cyanide costs I514 cents
per pound delivered at Marfil station, the present
terminus of the Mexican Central railroad; this price
is on the basis of 100% cyanide, but as sodium cyanide
contains 128 to 130% cyanide, the cost is actually a
little over 19 cents per pound; to this must be added
1.25 pesos, cr, say, 60 cents per ton, for transport to
the works, making the total cost about 19^ cents per
pound.
There is always some re-precipitation when
treating silver sulphide, by reason of the formation
of potassium sulphide, but this is diminished by the
addition of lead acetate, which forms a plumbous
hydrate that removes the soluble sulphides by form-
ing a lead sulphide and the potassium or sodium
hydrate. In practice, the re-precipitation of silver is
surpassed by the re-dissolving of it in the cyanide
solution.
By passing through cone-clasjifiers the product
escaping from the upper mill is divided into 'sand'
and 'slime,' which are treated separately, or in the
cyanide annex. In the 'sand' department there were
20 vats, each containing an average charge of 2,651.7
cu. ft., or 89.6 tons. During the month 1,792 tons
(dry) 01 sand was treated. The average assay-value
before treatment was 297.5 gm. silver and 1.37 gm.
gold; after treatment the contents were 52 gm. silver
and 0.1 gm. gold. In the 'slime' department there
were 82 vats, each containing 3,851.8 cu. ft. of wet
slime, equivalent to 24.26 tons dry. During the
t I
238
AMONG THE MINES OF MEXICO
4:i: »i
h' I
;1
/ ,..
Vii i
mo.uh, 1,989 tons were treated. The average assay-
value before treatment was 275.5 gm. silver and 1.3
gm. gold. After treatment the assay became 45.5
gm. silver and 0.1 gm. gold. The extraction was
85.17c as regards the silver and 707" of the gold in
the pulp treated by the cyanide annex, the total re-
covery by cyanidation being 417 of the assay-value of
the crude ore, so that the combined extraction by
cyanidation and concentration was 91.2 per cent. The
total cost of cyanidation was $4.13, and the consump-
tion of cyanide 1.9 kg. per ton.
Note should be made of the fact that successful
experiments with cyanide on silver ore had been made
earlier at the mines in Sinaloa, but the results had
not been heralded because they were obtained at
private properties, and even in these cases the official
tests of the cyanide company at Mexico City had
discouraged hope. The trouble was due to the use
of too weak a solution — a swing of the pendulum in
cyanide practice, for in its early .'i.s the main fault
was the employment of a needlessly strong solution.
Another factor that prevented success with these
silver ores, was the insufficient time given for
chemical action. The element cf time is especially
important in the case of concentrate, that is. iron
pyrite carrying gold free and silver as argentite; the
millman can afford to give the time required because
of the small quantity of this product and its richness.
'f;r
m
chapter 3t
METHOD OF TREATMENT IN TI.-^. BUSTOS MILL-
CONVEYING THE TAILING BY PIPE— THE STAMP-
MILL— CYANIDE PRACTICE — COMPARISON WITH
THE PATIO PROCESS.
EFERENCE has been made to
the milling practice of the
Guanajuato Reduction & Mines
Company in speaking of the
Bustos plant. It deserves
further consideration. Although
the property was acquired in
January, 1904, it was not until
Februar>-, 1905, that it was decided to build 80
stamps, rushing the erection of five of them so as to
afford experimental data during the construction
period. Many tests, on a large as well as a small
scale, had already demonstrated that a high extraction
of both silver and gold could be obtained from the
ore by cyanidation, and the experimental plant be-
came of great service in testing ores from different
parts of the company's properties, as well as to sug-
gest the detail manipulation best adapted to the main
plant, then under construction. The mines are a
mile from Guanajuato, and there are no streams
avnilable for disposing of the tailing; nor is there the
• i-ce necessary for accumulating residue on a large
[<
340
AMONG THE MINES OF MEXICO
t-
4
scale. It became necessary to discharge the i Hng
into the main stream of the di'^trict one mile fro' i the
mines, and this mean' the transport of all ores
through the heart of the Cit\ over an expensive rail-
road system, or the com Ictc scpanition of the stamp-
mill from the cyanide plant, the latter to he placed
upon the main strcai.
The Homestaki system, < . conveying iSie tailinj:^
in a cast-iron sevvc pipe, was adopted; it i an 8-i i.
vater-pipe of bell ..nd spigot type, asphalted, laid for
Its first few hundnd feet at a grade of 5%, then fla!
tcning to 2]/^^%. As it was desirable t ■ sett'c am!
return for re-use as much of the water cming fron
the concentrators as possible, allowing tht thii ; ilp
only to pass through the pipe, and to det rnune to
what poin^ st'ch thickening was possible, S( ral hun-
dred feet oi the pipe to be employed in this crk w -
put together and laid on* upon the actual graue.
Arrangem* ntv were mm! to circuit any rnen
(iuaiitity (■ ami (crushed in the stamps tli "x ffi-
iii ntal plain already installed) through lin- , -line
at my desired degree of dilution. Pul[ w. first
tried at a -rmal dilution of 8 i.t water t( 1 of sane
just as it cani'. from the tail )f the concentrate
fables; the water wa-^ then d inted by successive
strps, thickening the p-f -p, an , ' ri. were
made under the-e vary- g cox\<' on.>. Tt v de-
sired to remove a maxim nof< alf le ( jinal
water, and in the expersn ents tne -^ to 1 j dp \v.. ^ re-
duced to 2.5 to 1; and o success ally thai not o' H'
CUXMiYING TAILING THROUGi PIPE 241
cr '^i-
of !
pulf
ar ■
was ihe pipe not clogged with san«l, but the pulp at
tint thickness had such rapi ity of flow that it readily
lined r^st-iron nuts and othei iieavy objects with-
u; interrupting 'he strear T si. made by Mr.
I arid- Van Law irove tiiat pulp which has passed
tt ouirh a 30-mesl screen, with water in the propor-
ii n < 7'/2 to I, v.. li fl( w throuf h a launder of square
tior made of rough boards, set on a grade
\\ ih ^ V-shaped wooden launder, such
!' ow at ' 'ss grade aid with ess water. The
•H erimcter is thechii ictor.
pr n sett d, the proce as outlined as
is nsported ov- i railroad from
he mi^* jppe ttom cars, vhich discharge
' a ,c bin at tl, rusher plant. It is then re-
-ci! a No. 5 D. dates crusher to 2-in. size, dis-
arging over a picking-belt for moval of waste,
•hen re-crushed by a short-head N(
1-in. ring, then removed by cor
mill-bins, where ii is distribute
to cheap labor) proving mor-
use of a system of conveyor-beii
b with automatic trippers. Tlu
c icity for five days, which, togetl
bi- at the crusher plant, affords sutticiem storage of
ore.
The ore is then crushed under eighty 1,050-lb.
stamps of AUis-Chalmers make. The mortars are set
on a concrete f'.;.ndation, the anvil-block being cast
as an integral pave of the mortar. The latter has a
4 Gates crusher
yor-belts to the
ars, this (owing
ical than the
*:he top of a
!-bin has a
h the large
[i
242 AMONG THE MINES OF MEXICO
Steel liner, two inches thick, but there is 13.5 inches
of metal below the liner. Between the anvil-block
and the concrete a quarter-inch sheet of rubber is
spread. The mortar has a broad base— 36 inches
wide— provided with strong ribs at the sides.
The 30-mesh pulp resulting from the stamping is
concentrated over Wilfley tables, a considerable
amount of middling produced being removed for re-
grinding in an Abbe tube-mill and subsequent treat-
ment over separate concentrator tables. The tailing
from all the machines drops into concrete launders
and passes to the cones, where about half of the water
IS removed for use in the mill. The thickened tailing
then enters an 8-inch cast-iron pipe, laid with the
gradient above mentioned, and goes to the classifiers
in the Hacienda Flores, situated upon the main chan-
nel of the Guanajuato river. The classifiers are all of
the Homestake type, two sets of cones being used, the
lower one taking the bottom product of the upper
The overflow from both sets of cones goes to the slime
plant, the lower cone having an ascending current of
water.
The sand coming from the bottom of the lower
cones IS distributed, by the Butters & Mein device,
into either of two receiving-vats, each of 350 tons
capacity. These were planned to serve an ultimate
capacity of 500 tons daily, with the slime separated.
The receiving-vats are alternately filled and
drained, the discharge being made through bottom
gates onto ascending conveyor-belts, which pass over
PiPK-LiNE FOR Conveying Ta
TlBE-MlLL AT PaCHUCA
'i'
^ at -
U
^«ii^<^^jij;
THE HACIENDA FLORES
343
the centre of the line of eight leaching-vats, each of
the same size as the receiving-vats. In these a 14-day
treatment is given with 0.5% cyanide solution, the
sand being then washed and ultimately discharged
on conveyor-belts (running under the vats), which
deliver either into the river during the rainy season,
or to elevated storage-piles during the dry season, to
be sluiced during the succeeding rainy season.
The slime from the classifying cones is treated
by agitation with mechanical stirring and large cen-
trifugal pumps, which draw from the bottoms of the
vats and discharge over the tops, the total time of
treatment being four days. After the final wash the
slime is pumped into settling-vats 30 feet high, where
a further decantation occurs before the slime is dis-
charged, with a very small percentage of moisture,
into the river.
The entire plant, both the stamp-mill and cya-
nide annex, is designed so that it can be doubled, when
the stamp-mill will take a back-to-back form, 80
stamps with their concentrators being on either side
of the bins. The classifying-cones and the receiving-
vats of the cyanide annex are of sufficient size already
for a 500-ton plant, it being necessary only to add
another line of eight leaching-vats and the corre-
sponding slime-vats to bring the cyanide plant to the
larger capacity mentioned.
For roofing, corrugated galvanized iron on a
steel frame is preferred. As there is no load of snow
to fear, it is possible to use a light roof-truss. The
1
i^^^^^H
^5
:j^aMaHK
^]^^E
'^^^^^■^^B
jflVi
^^^^^^^^B
I^P
^^^^^^E
■
i^H
244
AMONG THE MINES OF MEXICO
H'-f* i!
native tile is cheaper, but it requires a heavier con-
struction, and does not afford as complete protection.
The Northerner will remark the lavishness of the
masonry about the mines and mills in Mexico. It is
the cheapest kind of construction and the native wood
is usually poor; it will twist and untwist as the dry
and wet seasons succeed each other, making it an
unsatisfactory structural material.
At the time of my visit there were 120 stamps in
operation in the Guanajuato district, and there were
205 tons being treated daily by cyanidation and 25
to 30 tons by the Patio process. Thus does the new
drive out the old. In 1887 there were 34 pattos at
work ; now there are only two.
In regard to cost in the Patio process, I have the
following data from the Hacienda de San Julio at
Pachuca :
Pesos.
Crushing, to pass 60-mesh in Chilean mills, with overflow discharge. . 3.60
Maintenance 0,50
Salt. 5%, or 50 kg. per ton 1.7S
Copper sulphate. Loss, 0.5% " " " l'2S
Mercury. Loss, V/, kg. for each kilogram >•'. silver 4.X
Transport from the mine 1.O8
Total i^
The ore is bought on the dump, therefore the cost
of transport is included. Salt costs 35 pesos per ton;
copper sulphate, 250 pesos per ton; and mercury, 3.41
pesos per kilogram. The average losses for the year
were 1.18 to 1.50 kg. per kilogram of silver extracted;
the loss of silver being 6.13 to 10.92% on the clean ore,
and 15.83 to 29.13% on the galena ore. The Patio
'^1«*£b-^
THE COST OF THE PATIO PROCESS 245
process waits on the completion of the chemical re-
actions, and it is therefore continued until extraction
ceases. Time is not considered; in winter it requires
20% longer by reason of the lower temperature of the
air.
At Parral, in Chihuahua, with the Russell
process, usmg hyposulphite, the cost of lixiviation and
roasting is 11 pesos, but the recovery is not as high as
It is with amalgamation on the patio, where the cost
IS 11 to 14 pesos, varying according to the manganese
content of the ore.
At Pachuca, by Mexican methods, the cost of
mining and sorting ore amounts to 15 pesos per ton-
the transport to the patio and the treatment there
add a further expense of 14 pesos, not including losses
or the expense of marketing the product. By stamp-
milling, pan amalgamation, and concentration, the
cost at Guanajuato was 8 pesos; and now by stamp-
milliiig and cyanidation the cost is 5.85 pesos. That
of mining and development is 3.50 to 4.50 pesos, so
that the total present cost is about 10 pesos, or $5
per ton.
At the time of my visit there were about 200 men
women, and children in the Anglo-American colony
at Guanajuato, the American element predominat-
ing. Of the 125 men employed, 75 to 80 were techni-
cal men, of good training. This made a strong piece
of mental machinery for industrial development.
C\)afUr 32
OLD METHODS— AN ABANDONED ARRASTRE— THE
HACIENDA DE ROCHA— MEN AND MULES.
^f;:^'
XAMPLES of old methods of
engineering, now becoming dis-
placed by the aggressive inroads
of technical science, are afforded
by two photographs that are re-
produced on the accompanying
pages. One shows a Mexican
drawing water by the aid of a
mule operating a lantern-gear wheel. In the fore-
ground is a channel, made of cement, along which
the water is directed for purposes of irrigation. The
adobe walls and pepper tree (perul) are typical of
Mexico. In front of the well there are two women,
one Oi whom is washing and the other gossiping. It
was ever thus.
On another page there is a photograph of some
old machinery at San Francisco, in the State of
Michoacan, and about seven miles from El Oro. In
the foreground is the pit of an arrastre; the cords that
attached the mullers or grinding stones to the re-
volving arms of the machine are easily distinguish-
able. The cord or riata is made of grass fibre,
although for this purpose leather thongs are more
usual. Motive power was obtained through the
wooden spur-gear operated by a water-wheel within
H"1
\ n
!)
iti
1
1
i 1
Pii
li('
j
1'
(li
mn't
ihf\ ■ i
i I
f
if
11
1
• .1
'1
An Oi.I' , Rxs
^•Siicfflk. .,ym3i
AN OLD PATIO ^^
the building, the wall of which forms the background.
The water-wheel is 20 feet in diameter and carries a
pm.on that gears with the crown-wheel on the ver-
tical shaft of the arrastre. One of the discarded (be-
cause worn out) grinding stones lies in the sunlit
foreground.
As the Patio process is surely destined to become
obsolete with the introduction of more rapid (and
therefore cheaper) methods of metallurgical treat-
ment, It ,s worth while to preserve an accurate record
of this old method of extracting silver from the ore
By courtesy of Mr. Bernard MacDonald, I am able
•"^ ^^^t'V^r^ P^^*" accompanying a report made
in 1866 by E. T.Ilmann. the Royal Commissioner of
Zl. I" ^'"''''" ^^^'^ h^^ ^'^'t^d Guanajuato
m 1865 at the instance of his own government to ex-
amine the mining practice then obtaining in the most
progressive parts of Mexico.
The plate opposite page 250 gives a photographic
view of the Hacienda de Rocha and a plan of the es-
tablishment, the various departments of which are
mdicated by letters, with an explanation in Spanish
on the margin. This is a good example of an old
haaenda de beneficio, the mechanical details being illus-
trated in five spirited drawings, all of which are here
reproduced. Fig. 23 shows the stamp-mill, with
wooden stems (*. b) shod with iron (r, c), resembling
those generally used in Mexico until recently. The
motive power is obtained from four mules harnessed
iVS!f-^S9l?SSI^B&M'
'^ "SZf
if'j I, I I r
\r
\^
248 AMOXG THE MIXES OF MEXICO
'i;i
\l
r;"'-*
F^
'?'
H
M
^
4
%
1
i
_
^^sii^:^ ^^r
OLD METHODS
249
Fic. 25.
.Ji jij|;'ii';'*fe' m'i
-i-ii^i^
', I!
350
AMONG THE MINES OF MEXICO
I : Vt
to the long arm (k) of a whim or malacate. The teeth
of the interlocking wheels are made of wood.
After being crushed under the stamps, the ore is
passed to the arrastre exhibited in Fig. 24. Here the
fine grinding was done. The mules are again in evi-
dence. The bed of the arrastre consists of stones
placed on end and the muller or upper grindstone (/)
is hung by chains {g) or leather thongs from the
radial arm {e) extending from the pivotal axis {a).
When it had been reduced to a fine pulp by the arrastre,
the ore was allowed to settle and thicken before being
taken to the open yard or patio where it was mixed
with magistral, salt, and quicksilver, as we have seen
at Pachuca. After being exposed to the air and thor-
oughly mixed by the tread of squads of mules, it was
conveyed to the settling-vats shown in Fig. 25, where
it was thinned with water, so as to allow the amalgam
to separate and accumulate on the bottom. Then the
amalgam was distilled in an iron retort of the shape
indicated by Fig. 26. This resembles the one .s -n in
the Hacienda La Union, at Pachuca, and described
on a preceding page. Finally, in the last drawing
(Fig. 27) there is an excellent rcpresentati. n of the
manner in which the cast-iron hood was raised when
the distillation of the mercury was completed, dis-
closing the sponge of silver that remained in the re-
tort. This silver was melted into bars.
"By the wayside of progress lie the broken images
of the past."
|ii
i
mmm
') .(1
Vi
o
z
9
, l.
RETORTING THE AMALGAM
251
1 ^1
^^^^B'
^^^^^^^^B
ilB''
Fig. 27.
I
I
C^KipUr 33
THE FLOOD AT GUANAJUATO— THE HUMOR AND
THE TRAGEDY OF IT— CONCLUSION.
Hi
l», ♦■■
H
UANAJUATO had a flood, and
like that of Noah, it serves as a
new starting point in local his-
tory; things happened B. F. or
A. F. The catastrophe occurred
on the first and second days of
July, 1905, so that the recollec-
tions of it were still vivid at the
time of my visit. Unusual tropical showers poured
upon the neighboring country, and the waters con-
verged from a steep watershed into a narrow ravine
choked by bridges and crowded with dwellings.
Never wide, the bed of the Guanajuato river had
been elbowed by roads, houses, and debris, so that in
places there was left a channel only two metres deep
and four metres wide. Furthermore, it was ex-
tremely tortuous, the original course of the river
having been repeatedly diverted to secure space for
buildings. On the first day, the water rose to a level
which just exceeded that of the flood of 1873— about
four feet above the street. On the second day th-^
volume of water doubled, it rose 15 to 17 feet
above the pavement, and made terrific havoc among
the soft masonry and mud walls of the old town,
which melted like salt before the onrush. A few
THE FLOOD
2S3
minutes sufficed to cause the collapse of many build-
ings, and to create fearful confusion. At that time a
sewer was being constructed at the upper end of the
town, near the Presa, and the timbers of this were
torn out, to be carried forward so as to form a batter-
ing ram, demolishing the adobe walls and choking
the confined channel of the torrent. Officially it is
stated that 54 were killed, but 73 were carried to the
morgue, and it is probable that fully 100 people per-
ished. Many Mexicans from the outside country
happened to be visiting the town, it being the time of
a fies/j, and of these a number were never accounted
for. No Europeans or Americans were drowned.
At the time, there was nothing humorous about
the disaster, but,' with that happy instinct of hu-
manity, as the horror was forgotten, some of the ab-
surdities were remembered. To the natives it was an
opportunity for spoil; looting was general. "Es un
Tcgalito de Dios a nosotros que no sabemos trabajar —"it
is a little gift from God to those of us who don't know
how to work," so they said to themselves. Some of
the peones laid their hands on a shoe-store that had
been devastated, and to this day they can be seen
wearing a tan shoe on one foot and black leather on
the other. The pink and green steamer-trunks of
an American lady glorified the torrent for a while-
they bobbed under the arch of a picturesque bridge,'
and Ian -led in the second story of a needy native. A
mule was borne by the flood into another second
story, and in his terror he bit into a box of Ivory soap,
>4i
(■•^
i i
254
AMONG THE MINES OF MEXICO
and it was this that buoyed him across the waters.
Billiard tables, with their slate rops cruelly exposed,
were engulfed in the whirling debris. Seventeen
pianos and two cannons meandered down stream to
the sound of many waters and their own spontaneous
accompaniment. An azure splendor suffused tiie
scene as a box of bluing irom a laundry made its
vivid passage; whereupon the pianos played a fa-
miliar waltz of Strauss. Bolts of silk appeared among
late mules and defunct pigs, street-carp were seen
with men balancing on their unsteady decks until the
upper windows of a church offered shelter. The
Teatro de Juarez received a complement of burros,
and the compliment of their lamentations, which
simulated grand opera, ju'^t as the sequel imitated
Noah's Ark, for when the waters subsided, they made
their timid descent down the grand staircase with alt
the dignity befitting a momentous occasion. But
worse things than these happened ; a case of Saratoga
whisky floated onto the desk of a total abstainer — and
the owner of the whisky never saw it again.
With the downpour of rain came darkness, tiM
natives lit candles, and the women came o«t on th«
balconies with lights, wherewith they made the s^
of the cross, the church bells were rung, and to the
natural horror of the scene was added a touch of
solemnity. This was on the first day; when the sec-
ond flood came in the late afternoon of the second
day, with its repetition uf an uncanny darkness, the
people crowded to the adjoining hilltops, which
y^8yg!r»'Sf«RJggg'« .il!, i BUJU-JLIU i lliiL i ijllll
.^^^im'* '— .-■.i««t-i-r*i«r»
fill.
f
li ,
I
CONCLUSION
255
were brilliantly illuminated with moving candles,
while the air vibrated to a thousand bells. To them
it was the end of the world, and we, of San Francisco,
who saw a greater devastation, can well imagine that
to their simple minds it seemed a horror beyond
explanation.
And so I come to the end of the notes that record
my recent travels in Mexico. To speak in the lan-
guage of photography: I brought some films from
Mexico; most of them were only snapshots, there be-
ing no opportunity to get time exposures ; therefore
the images that I have delineated, and the impres-
sions that I have tried to convey, may lack definition.
But beyond the mental imprints which it has been my
endeavor to transfer to the pages devoted to this
account of a journey in the southern land, I brought
other memories and experiences, which were never
developed ; they remain blurred, and to none but my-
self have they a meaning. I have recollections of
multi- jlored facades, of sunlit walls, and cool patios,
the sound of bells, and the cracking of whips, cries of
cervcza and frijoles, conical hats and hooded women,
a stream of chocolate-colored humanity, a politeness
that gave dignity to the commonplace, a squalor that
soiled romance, and a sunshine that glorified every-
thing; and then, like the refrain of a song that we
love, the kindness of the men of my oWn race, and the
hospitality of women who make every abiding place
a home. And so, Vjyan con Dios ma amigos.
V
i
I
1
'U
"Across t()e
San 3uan Mlountalns
Being the account of a ride over the mounuinou*
mining region, of Southwestern Colorado, in
September. 1902. Reprinte-i by per-ni„ion from
I he Engineering and Mining Journal
it .1
I
.3 ' 1
^^^V^^^^Te.
I
■A.l.
, I i
ii
|.i
k
s^.
i
f
ii:
ConUnti
(rhapter _
Page
I. The Start from Ouray. Visit to the American Nettie
Mine. Clastic Dikes. A Picturesque Tramway i
a. The Bachelor Mine. Trail Horses and MounUin
Transport. Miners' Cottee. A Strange Dike.
The Theory of Its Formation. Description of
the Bachelor Lode
3. Across the Range to Telluride. Mountain " Roads.
The Camp Bird Mill. Treatment of the Ore.
The Local Geology. Electrical Power . 20
4- The Camp Bird Mine. .Story of Its Discovery by
Thomas F. Walsh. On the Top of the Range.
Arrival at Telluride 28
5. Mills and Tramways of Telluride. Operations at a
High Altitude. Snowslides and Their Effects -2
6. Destruction of the Camp Bird Mill. The Assassina-
tion of Arthur Collins. Labor Riots . . 38
7. The Smuggler-Union Mine. Structure of the Lode
o ^ Geological Conditions. Variety of Minerals . 44
8. nie Contention Mine. An Aerial Voyage. Good
Mine Management
9. On the Way to Silverton. The Bridal Veil Falls.
Fine Geological Section. Ophir. The Red
Mountains
10. Silverton and Its Early History.' The First Smelters
in Colorado. Pioneers of Industry. Rapidity of
Development f-
11. The North Star and Silver Lake Tramways.' Some
Uever Engineering. Comparisons. Double and
Single Ropeways. Eureka. Veteran Miners. . 66
lit
MICROCOPY RESOLUTION TEST CHART
ANSI ond ISO TEST CHART No 2
1.0
I.I
i ;f iiM
t 1^ ill 2£
1.25 jjiiju
1.8
APPLIED IK/MGE Inc
Rorhesler, Nc» Tork '4609 jSA
I 7 'ft) *«;■ nlOO - Phon#
CONTENTS
M
/ \
* «! If
•
R'
Chapter
12. The
Page
IS-
M-
IS-
i6.
i8.
19.
20.
21.
Cinnamon Pass. Electrical Transmission of
Power. The Tabasco Mill. Burroughs Park.
The Secondary Enrichment of Copper Veins. . 75
The Golden Fleece. A Bonanza and Its Vicissitudes.
Geological Features. Theories of Lode Forma-
tion. The Treatment of the Ore 80
Slumgullion Gulch. Landslides. The Cannibal Pla-
teau A Grim Tale. Rock Disintegration. A
Natural Cathednii 87
The CeboUa Hot Springs. Thermal AcMvity in the
Rocky Mountains. Its Relation to Ore Deposits.
Th'- Gunnison Plateau 92
Vulcan. The Good Hope Mine. Geology of the
Vein. Native Sulphur and Tellurium. Acid
Waters. Theories of Origin. Rare Minerals . 95
Gunnison. The Derelict of a Boom. Crested Butte.
The Irwin District. Silver Vein in Sandstone.
Anthracite. The Smith Mine 105
The Coal Mine at Floresta. How Anthracite Is
Formed. Methods of Mining. The Breaker.
A Panoramic View '12
Over the Ohio Pass. At Gunnison Again. Fishy
Yarns. Gate View. Poetry and Geology . .119
Lake City. The Ute and Ulay Mines. Concentrat-
ing Mill. Electrical Drills. New Mills . . 123
Rose's Cabin. Climbing the Range. A Snowstorm.
Bear Creek. After the Storm. A Glorious Pic-
ture. Arrival at Ouray 127
n ■■ '■
! '(
1 ' ■
IV
TCul of HUuslraUons
Facing Page
The Amphitheatre of Ouray 4
The American Nettie Mine, near Ouray 5
Pack-Train at the American Nettie Mine 6
Mules Laden with Lumber for the Mines 7
Pieces of the Qastic Dike in the Bachelor Mine . . . . lo
A Prospector and His Burros H
Sunshine and Shadow on Snow. The Silver King Mine . I2
The Camp Bird Mine I3
In the Heart of the Mountains i8
Mt. Potosi 19
Mt. Abram, near Ouray. A Bit of Geology on the Road-Side 24
Hauling Concentrate from the Camp Bird Mill .... 24
The Revenue Mills, near Ouray 25
The Crest of the Range and the Upper Workings of the
\ --ginius Mine 25
Mt. \\ ilson and the Valley of the San Miguel 3°
Savage Ba;in 3^
The Liberty Bell Mine 36
The Bullion Adit of the Smuggler-Union Mine .... 37
Looking down Canyon Creek 38
Camp Bird Mill Burning 39
Destruction of the Camp Bird Mill Ly Snowslide and Fire . 42
After the Fire at the Camp Bird Mill 43
The Smuggler-Union Mills at Pandora 44
The Smuggler-Union Mill at Pandora 45
Smuggler-Unluu Tramway. A Load of Lumber .... 52
Marshall Basin 53
Looking Backward from the Bridal Veil Trail ... 54
Telluride and Its Geological Section 55
V
} "'I
■I ft
^:
l.i. !
I !
'<-.S
W
LIST OF ILLUSTRATIONS
Facing Page
Timber-Line. At ii,ooo ft. above Sea-Level 58
The Ophir Loop. The Village of Ophir in the Valley
Beyond 59
Silverton 60
The Mines of Red Mountain 61
Breaking Trail Through the Snow. 'Man in the Bucket.'
An Easier Mode of Travel 68
Rope Tramways 69
A Pack-Train on the Way to the Old Hundred Mine, in
Cunningham Gulch, near Silverton 76
The First Snow. Silver Lake Trail 77
The Toll Road between Ou.uy and Silverton 82
The Valley of the Uncompahgre 83
Yellow Mountain. Early Snow 94
Vulcan. Burroughs Park 95
Diorite Contact on Silver Mountain, near Ophir . . . .102
Looking Down the Valley below Red Mountain .... 103
Mt. Teocalli. A Highland Meadow 106
After Riding 400 Miles 107
The Portals of the River i"
Mt. Sneffels "3
After the Storm. On the Crest of the Range 128
Ouray 129
VI
a
TLlsl of T)rawln3s
Figure Page
Map of Southwestern Colorado 3
1. Pockets of Ore 4
2. The Bachelor Dike 11
3. A Cross-Section 13
4. A Disappearing Fault 15
Section of American Nettie Orebodies 18
Dike of Gilsonite 19
5. Section Along Uncompahgre Creek 25
Map of Telluride District, Colorado 27
6. The Smuggler Vein 46
7. Another Section of the Smuggler Vein .... 47
Cross-Section of the Contention Lode 50
A Fault- Vein Faulted 54
8. Section Along the Golden Fleece Lode .... 82
A Lode in Quartz-Schist. Mew Zealand .... 94
9. The Good Hope Vein 97
10 and II. Examples of Vein Structure 99
12. The Ruby Chief Vein 109
Upturned Strata of the West Slope of the Elk
Mountains iii
13. Porphyrite Dike in Sandstone 115
Geological Map of the Anthracite Region . .116
The Laccolith of Mt. Marcellina 118
Gothic Mountain. A Trachytic Mass Overlying
Cretaceous Rocks 122
vu
li.
-1
ytl-'i ^t''t
< i
*
1
. .1,
':' •'' '1
1
11
II
\ !
!'^!:
f
a
mi
\i
ik
,1K
"l^cross tl>ft
San ISuan 2^ountaiR5
(Li)aphr X
THE START FROM OURAY— VISIT TO THE AMERI-
CAN NETTIE MINE— CLASTIC DIKES— A PICTUR-
ESQUE TRAMWAY.
N a superb morning in
September, that month of
many colors, four of us'
started on a ride among
the mining districts of the
San Juan in southwestern
Colorado. The starting
point was Ouray, the pic-
turesque little town named
after the old chief, an In-
dian of renown, the friend of the white men that first
explored the mountain fastnesses of the Uncom-
pahgre. From Ouray we rode across the ranges to
Telluride, Silverton, Lake City, Gunnison, and thence
to Crested Butte and back, following a course which,
' The party consisted of H. N. Tod, Lionel Lindsay, C. H. Wittenoom,
and the writer.
W^MM&
m
i ft
ACROSS THE SAN JUAN MOUNTAINS
I,*
'i ^ t
'VUlV
h
rii;
on the map, looks like a ug ire 8, with Ouray at the
base of the lower loop md Crested Butte at the top.
See map. The distance was slightly over 400 miles;
the country traversed is beautiful to the traveler and
interesting to the mining engineer, so that the experi-
ence was sufficiently rich in incidents and information
to warr t the account which it is my purpose to
preser
^ left Ouray early on the 5th of September,
1902, with the intention of visiting two mines in the
vicinity — the American Nettie and the Bachelor. A
mile below the town the trail ascends the precipitous
sides of Gold hill, and as our sure-footed mountain
horses followed the zig-zag through the pines we
found that each turn of the trail brought a steadily
expanding vista until, halting on a projecting rock,
we could see far out toward the north to the table-
lands behind Montrose, across the near valley to the
terraced dip-slopes of Triassic sandstone, down upon
Ouray itself, cradled amid red rocks and golden
aspens, and up beyond the town to the sentir<l peak
of Mt. Abram, which guards the sourc r
swiftly flowing Uncompahgre.
On arrival at the American Nettie mi . me
superintendent, Mr. Kunz, permitted us to visit the
underground workings. These have an aggregate
length of 12 miles, and consist of a series of adits and
drifts penetrating the top layers of the Dakota sand-
stone where it comes in contact with the overlying
black shale of the Colorado series. Both formations
ilfiiCL
MAP O^ SOUTHWESTERN COLORADO
ftouxt foiioamA"
(!-
r ■■ *' ' ■!
i' 1
1 J..
j
1 14.^1
4 ACROSS THE SAN JUAN MOUNTAINS
are members of the Cretaceous, the Dakota being the
basal member of that division. The ore is found in
irregular masses occupying chambers in the sand-
stone and impregnating the rock along stringers or
small veins, which serve as a guide in prospecting.
In the cavities the ore consists chiefly of a sinLery
mass of oxidized material, earthy and red, but when
the ore is found impregnating the body of the sand-
stone it appear^ in the form of sulphides — iron and
copper pyrites, blende, galena, and gray copper. The
r/r.
£3 SM»JTtN« Sill«l.t E7 0»fc
Fl»>«.
best ore seems to iiug the contact with the overlying
shale, in the manner illustrated in Fig. 1, where A and
B are 'pockets' of ore reaching downward from the
shale-sandstone parting and connected by a seam
X T, which follows the line of division between the
two rock formations. The pockets are full of crumbly
oxidized ore intermixed with a little gypsum, while
X T also carries some gypsum and a thin layer of
black crumbly lime-shale, which suggests that it
originated from the dissolution of an impure gypsum.
The bedding is flat, with a slight dip to the northeast.
<."^'-^m^mw^m\
.JS^.
r'lif^..
i
%,S^^ "'•
^iwm^
^1
I i:'
, n
.1 1,
^: !«
^\\\
h
, ' I
i
.1.
f
i:l|
i'! 1
I<mM
H^ikM,
1^ ""^^^-^
"M.
^MHn.^ y
' ' * jiei^^ ^^
P^<Si>{
AMERI' \N NETTIE MIME 5
;.n(l the formation is crossed by almost vertical dikes
which have evidently been the immediate cause of
siicii fracturing of the sandstone as was favorable to
sul)sc(|Uont ore deposition. In prospecting, it is found
best to follow stringers o»" yrite or even mere 'walls'
(slight fractures devoid ' .)re) that are parallel to
tlu' course of the dikes.
These dikes are peculiar; ihey are not mad** r" ."
volcanic rock ; on the contrary, they consist of cb
matf-rial, that is, fragments of sedimentary rock; in
the /^ nerican Nettie mine the fragments were recog-
nizable as pieces of sandstone, probably derived from
beds not far away. The dikes thr" we saw were 2 to 4
feet wide, and were well defined by their distinct
walls; the country near them was fractured and
sheeted, a condition probably due to the disturbance
brought about by the intrusions of volcanic rock,
which are known to occur in certain parts of Cold
liill. Not that the clastic dikes are of direct volcanic
origin — quite the oontrary; the -re built up entirely
of sedim.^ntnry rock material, v, h has been packed
together and cemented 1 v the ..ater that has found
its way into them; the^ .ccupy fractures that may
have been, anr' nrobabl\ ,^ .-re, the indirect result of
an intrusion, t • ' vsgh the neighboring formation, of
true eruptive matter, such as has been referred to as
actually occurring near-by. On the high ridge above
tlie American Nettie mine there is a coarsely porphy-
'From the Greek, kla^tns, tiroken. It is employed to describe
rocks made up of fragments, as distinguished from the crystalline.
£1
f
^1
\
Jv- -^*p«^^-wm^ . . , w:mv':fw^w^^m^
ACROSS THE SAN JUAN MOUNTAINS
! ^
I '
'M < f
ritic diorite, which suggests an agency capable of
having brought about the fracturing that led, first,
to the formation of the clastic dikes and, subse-
quently, to the circulation of the ore-depositing
waters.
The American Nettie has a new tramway, whose
catenary curve sweeps om the high cliffs of Gold
hill, and, with undeviating line, bridges the abyss of
the valley. It is a picturesque bit of engineering. A
descent of 1,820 feet is made in 4,200 feet. The span
that crosses the valley is 2,100 feet long, and in that
distance the drop is 915 feet. The engineers of
the Leschen Company built it and, owing to the
abrupt contour of the ground, they had to make
especial provision for safety. The descending side
has a cable IJ/^-inch diameter, while the cable
upon which the empties return is one inch in
diameter. The traction rope is ^ inch. To the
latter, button-shaped clips are permanently attached,
with intervening spaces, the length of which is regu-
lated by the number of buckets in use. The buckets
are automatically detached and attached to the rope,
at the loading and terminal stations; at both terminals
the buckets receive a retarding and accelerating
movement, as they arrive and depart, respectivcl}, in
order to diminish the vibration attendant on the re-
moval of the load from the line, and the return of it
into service.
X
I
f 1
n
■XI
•il
'■H
K^^
HHi
^■yHi
^^B^^Hfir
^^IB^
UK
1
•I
, 1
'\h\
n ^
m
H)
f I
>
i
!-:l
Is- V'i
1 ' '
llilli
i
Cl^apter 2
THE BACHELOR MINE— TRAIL HORSES AND MOUN-
TAIN TR..NSPORT— MINERS' COFFEE— A STRANGE
DIKE— THE THEORY OF ITS FORMATION— DESCRIP-
TION OF THE LODE.
FTER leaving the American
Nettie mine we followed the
trail that took us around the
northern ramparts of Gold hill,
down into the valley, whence a
road led to the Bachelor mine in
Red canon. Two members of the
party, who were unused to the
mountain horse, marveled at his sure-footedness as
we scrambled down talus slopes and threaded our way
among loose blocks of fallen rock. It is my experi-
ence that a good 'trail horse' will go almost anywhere
that a man can go without using his hands, while the
patient burro (donkey) will walk safely over ledges
which bring a tremor to the hearts of those who are
not mountaineers. All the exploratory work of the
Rocky Mountain regions was done by 'packing,' that
is, by the transport of supplies and machinery or the
backs of animals. Both mules and donkeys are used
in this service. When the former are employed they
arc strung out in a line and connected by rope. A
man rides the leading mule and guides the whole
II
,f
ACROSS THE SAN JUAN MOUNTAINS
■\l
M>
? 1
cavalcade. Another man usually walks or rides in
the rear. When burros ( the word 'donkey' being
rarely heard in the mining regions) are engaged in
packing they are not tied together, but each goes
loose, and the owner drives them like a flock of sheep,
though differing from the latter in that they have
learned, from the narrowness of the trails, to walk in
single file when that is required for safety. A mule
will carry 250 pounds up grade and 350 pounds down,
while a burro can manage to carry an average of 200
pounds. The mule requires to be fed, but the burro
can eke out a precarious existence on the scant grass
of the mountain slopes, and for this reason he has
been most serviceable to the pioneer and the pros-
pector; if the camel be named 'the ship of the desert,'
the patient long-eared friend of the miner mighL well
be christened 'the porter of the hills.'
When we reached the Bachelor mine the noon-day
meal was ready, so we accepted the invitation of Mr.
George Hurlbut, the principal owner of the property,
to take luncheon before going underground. It v:M
not be out of place to refer to the food that miners
get in localities like these; it is surprisingly good, as
a rule, even at mines which are a couple of miles
above sea-level and a corresponding distance from
the main distributing points for provisions. The
companies usually charge one dollar per day for
board and lodging, where standard wages are $3 per
shift. The f^re which the miner gets three times a
day is superior to that of the second-class hotel of
i |i :^
MINER'S FARE
the neighboring mining towns and far better than
that which is the daily portion of workmen in other
countries. There is always one weak spot — the
coffee; partly because it is nt prepared immediately
before being se/ved and partly because it is made
from adulterated mixtures, and largely because the
average mine cook does not know the tast< )f real
coffee — at all events, it is a concoction out of Keeping
with the excellence of the remainder of the miner's
fare and much better adapted for staining floors or
removing boiler-scale.
The Bachelor lode is closely associated with a
clastic dike of peculiar <.haracter; the same lode fol-
lows the dike through the mine to the east, the Khed-
ive, and to the west, the Wedge. Light-colored
sandstone and shale, belonging to the upper sub-
division of the Triassic, constitute the prevailing
formation; their dip is slightly southeastward and
they are crossed almost at right angles by a dike,
which inclines a little to the north and follows a fauit-
iissure of small displacement. In the Khedive the
sedimentaries form a low monoelinal fold broken by
the dike-fissure, with an amount of dislocation so
slight as to be difficult of measurement. The zinc-
lead-silver lode of the mine traverses both dike and
country. When small it usually follows one or other
of the walls of the dike, and when enlarged it spreads
out into both dike and country. The lode haf
northing of 45 feet in 480 feet, but this is due not
niuch to the angle of the dip itself as it is the
fi
I '•
u:m
• i !
Hi I
H
10
ACROSS THE SAN JUAN MOUNTAINS
result of frequent oflFsets caused ')y slips along the
bedding-planes of the country. These do not fault
the ore, because they antedate it, but they cause the
vein to diverge to one side in accordance with the
course of the fracture along which the dike first, and
the lode-forming solutions afterward, f^nnd a pas-
sage. The ore frequently spreads out between the
bedding-planes of the sandstone and shale; it is also
found in seams following fractures in the outer
country that appear to be sympathetic to the main
fissure occupied by the dike and the lode proper. The
dike is usually about two feet wide.
The dike, as seen in the Bachelor workings, is
called by the miners, of course, 'porphyry,' but it con-
sists of fragments of quartz, from sub-angular pieces
as large as a thumb-nail to grains of sand, and of flat
pieces of black shale; the latter are prominent, and
give the dike-rocl a distinctly mottled appearance,
as the accompanying photographs' show. They vary
in size from microscopic fragments to bits several
inches long. Besides these the dike contains pieces
of sandstone, often micaceous by reason of sericite.
A characteristic of the dike-rock is the arrangement
of the shale fragments with tlicir longer axes parallel
to the walls of the dike; this is more marked in some
parts of the mine than in others, and it is usually
most pronounced close to the walls. (See Fig. 2
and 3.) The latter form a distinct parting from the
•These photographs I owe to the courtesy of Mr. Ransome and the
U. S. Geological Survey.
'm<j':^m
Si
1
I
•■4
i
^ 1 ■■
m
ill
•
''IM^I
U
THE BACHELOR DIKE
■ ■ -Vv* ^ ^- i' '•'/■>• V'r-T — ■
■'—-— I ')*■ ' i i''W"l :\t 'Ml i' ' , ' ''
1% X'.:jr'}:l:,\i.l
Fig. 2.
II
!'
Ill;
( ^'
\\..f.
I \ >!•
r'
-15
, 1
»'
" 5
i f^
M '
-.]
f
'i'
^ i
I ^
Il-
ia ACROSS THE SAN JUAN MOUNTAINS
outer country, and sometimes are also accompanied
by a sclvape.
This, like the one we saw at the American Nettie
mine, is a clastic dike and the origin of it affords
Riiod material for speculation. F. L. Ransome, of
the United States Geological Survey, has contributed
an interesting paper* on the origin of this very dike,
and he explains it thus:
"A fissure was formed, accompanied by some
faulting, and was filled, chiefly from above, by frag-
ments of the soft fissile black shale, which does not
occur in the stratigraphically lower beds exposed in
the immediate vicinity, and partly by material from
the lower light-colored beds forming the present
walls."
That this pseudo-dike is built up of fragmentary
sedimentary rock, that it occupies a fissure, and that
it contains no lava or other volcanic matter as a
cementing material — these facts seem to be assured.
The nice point about the problem is the mode of
formation. Was it from above or below? Mr. Ran-
so- accepts the first alternative, and in support of
this view he is enabled to instance the sandstone dikes
that Whitman Cross found in the granite near
Divide, in Colorado, that, elsewhere, Darwin,
Ussing, Irving, and others have described, and as-
cribed to a filling from above. Hugh Miller found a
pseudo-dike in Cromarty (Scotland) in which a mass
"A Peculiar Clastic Dike near Ouray, Colorado, and its Associated
Deposit of Silver Ore,' by F, L. Ransome. Transactions American Insti-
tute of Mining Engineers, Vol. XXX., ,p. 227-236.
u:
•A
Z
■fi
y.
■7.
}
A CROSS-SECTION
»3
3
'J
/ . ' ^ ' I. M ° • 'I L\ '
• '""rX•V'•^'L:-
-• I Fiir
Tis ,
S«N()iT«NJ 4M> JH^ie ({{y] CL-tiTlC B(«t
14
ACROSS THE SAN JUAN MOUNTAINS
of sandstone working in from above (probably) con-
tained fossils. Diller wrote a memoir' on the sand-
stone dikes of California and concluded that they
were injected from below.
In the Lipari islands there occur masses of vol-
canic tuff, hard enough to be fractured, which exhibit
cracks filled in with fallen dust and scoria." But this
is an entirely different kind of occurrence, as also is
that observed at Pontgibaud (France), where a silver-
lead vein occurring in granulite is shattered, together
with its encasing rock, and, for a length of 10 metres,
at a depth of 50 metres, contains boulders of scoria-
ceous lava evidently derived from the alluvium that
once covered the outcrop of the vein.' It is obvious
that occurrences of this kind, at surface or near it, are
quite different in their origin from a clean-cut frac-
ture many hundred feet underground, of great length
and depth and persistent width. It is, however,
worth while to emphasize the distinction.
As between filling from above by gravitation
and filling from below through pressure, I am de-
cidedly inclined to choose the latter. In the first place,
no mining engineer familiar with the shifting of wall-
rock would grant the idea of the maintenance under-
ground of an open fissure, both large and crooked, in
rocks so soft as these shales and sandstones, for a
'Bulletin Geological Society of America, Vol. I., pp. 411-442.
" My authority is my friend, Professor John W. Judd, author of 'Vol-
canoes' and Dean of the Royal School of Mines, London.
' Engineering and Mining Journal, p. 151, August 18, 1894. 'The Lodes
of Pontgibaud,' by T. A. Rickard.
I Tl
f :
i .'If r
A DISAPPEARING FAULT
0^ ^\
IS
i^\|^fe^3
•-^^iirf^
t . 1 SANDSTONE ^--:_=:] SLACK S.HA1.E
l^j£rJ LIMESTONS
LIME SHALE Fig. 4.
p
I^BKi
^^BIHIB
f^B^^H
<K
1 ^Sfl^s
Mm
H^'
i "i
:i '1
(fi,
f
16
ACROSS THE SAN JUAN MOUNTAINS
period long enough to permit of the complete filling
up of the supposititious crevasse. The sandstones and
their alternations of shale exhibit movement along
the sloping bedding-planes, as: might be expected, and
in the mine care has to be exercised to prevent injury
from the rock that breaks off along these partings.
Next, the internal evidence of structure appears to
be against such a view. Fig. 3 illustrates a note-
worthy characteristic of the Bachelor dike, namely,
the frequent tendency to bulges and to vein-like pro-
trusions, which extend from the body of the dilv^
upxL-ard into the surrounding country. No downward
filling would, so it seems to me, explain this condition
of affairs.
The fragments of black shale are traced by Mr.
Ransome to an overlying bed through which the dike
does not penetrate. Because it does not pass through
this shale bed it is inferred that the latter was the
source of much of the shale scattered through the
dike. But why should not a simpler explanation
suffice? Namely, that the fissure occupied by the
dike broke through the harder sandstone series and
died out when it met the tenacious, shifting, and more
flexible layers of shale, much in the manner observed
in the Enterprise mine. (See Fig. 4.') Finally,
it is said that the black shale does not occur in the
lower beds observable in the vicinity of the mine
•Taken from Transactions American Institute of Mining Engineers,
Vol. XXVI., p. 944. 'The Enterprise Mine, Rico. Colorado,' by T. A.
Rickard, pp. 906-980.
THEORIES OF ORE FORMATION
17
workings. I thought so too, until, on the occasion
of my second visit, I noticed an exposure of black
shale near the roadside at a point a short distance
below the Bachelor mill, and, presumably, not much
deeper than the present workings of the mine. This
points to the probability of there being other layers
of black shale within the sandstone scries traversed
by the dike and renders it unnecessary to go far afield
for a possible source of the black slivers so charac-
teristic of the clastic rock. May it not have hap-
pened, therefore, that the dike was formed by the
crushing of sandstone and black shale along the line
of a fissure which was filled with this material as the
fissure was slowly formed, much as water rises into a
crack through the overlying ice ? The close packing of
the material within the dike, as is indicated by the
arrangement of fragments of shale parallel to the
walls, is indicative of subsequent pressure, and it is
not without a further suggestion that greater pres-
sure, but from below, may have originally pushed the
clastic material upward into the fissure as it was
formed. Water may have I ; ?i present to give addi-
tional mobility to the broken matter, such water
subsequently having been largely expelled by the
squeezing in of the fissure-walls. Professor J. W.
Judd examined some specimens of thv Bachelor dike
which I sent to him, and he concluded that the con-
solidation of the fragments was due largely, if not
entirely, to the later chemical action of percolating
solutions. To this suggestion there is the evidence
H i
II;.-
( , (
1
i i i ,: ■
i8
ACROSS THE SAN JUAN MOUNTAINS
afforded by the subsequent deposition of ore along
the course of the dike.
In Fig. 2 and 3 the Bachelor dike is illustrated.
Fig. 2 exhibits the relation of the vein to the dike.
J B is quartz carrying streaks of galena and gray
Bladt carbon
•ccous Shalt
40'»
■:-',-'''' ''- -V-,' -\r'-)''~'"'.
Clay and
aandy Shal
Section of AMERtcAN-NETTiE Orebodies.
After J. D. Irving, U. S. Geological Survey.
copper (tetrahedrite). There is also some blende
present. Inclusions of country (sandstone) give the
vein a mottled look along its outer edge, between D
and E. The clastic dike B C contains several large
pieces of shale, and a few signs of ore. The fractures
alongside the dike at X appear as dark threads of
sulphides. In Fig. 3, taken at the east breast of the
main drift in the adjoining Khedive mine, the clastic
material is 17 inches wide, and exhibits one of those
vein-like branches or off-shoots that are not uncom-
mon. In this regard the clastic material behaves just
like a lava. The set-off at the top of the section is
n
In thk IIkakt of thk Moint.mns
Si
IP
^'«»^
r H
Jl
V
^P'ii
m^
11
-('. Mt^P
i^^m¥
llP
■P
11'^
11
m
iil
11
» ■:- -M'-t^t
-iriU.^
i'\t
m
.,n 'if
ti
' t
i' 1 li :i
M%
GILSONITE DIKES
19
also a common feature. Sympathetic fractures occur
in the encasing rock. In this instance the vein had
merged into the dike and could only be seen vaguely
in the form of patches of ore within the body of the
dike.
Dike of Gilsonite.
After G. H. Eldridge, U. S. Geological Survey.
The whole occurrence is one of great interest.
If these clastic dikes are studied with reference to
true lava dikes on the one hand and veins of
asphaltuni or gilsonite on the other hand, it should
be possible to arrive at a clearer idea concerning
the manner in which rocks undergo the fracturing
that precedes ore deposition.
1
tl
■ ^
I it I
C()apter 3
ACROSS THE RANGE TO TELLURIDE— MOUNTAIN
ROADS— THE CAMP BIRD MILL— TREATMENT OF
THE ORE — THE LOCAL GEOLOGY — ELECTRICAL
POWER.
HE next day, September 6, our
cavalcade clattered up the main
street of Ouray on our way to
Telluride over the Mt. Sneffels
range. Cloudless weather, not
unusual after the rains of late
August, made the ride up
Canyon creek to the Camp Bird
mill a stimulating pleasure. Much of this road is
cut out of the solid rock, in many respects it is a fine
example of mountain engineerinj;,, and it is kept in
good order because it serves as the avenue of traffic
for two of the largest mines in Colorado — the Reve-
nr and the Camp Bird. This part of Colorado owes
much to an energetic little man who began by being
an Indian interpreter, became a road-builder, and
finally developed into a successful railroad organizer.
Otto Mears is called the Pathfinder of the San Juan:
he has left a monument as enduring as Thorvvaldsen's
lion of Lucerne, which lies sculptured in the rock
above the Swiss lake; and much more useful, for
the roads that Otto Mears built into the sides of the
cliffs overlooking the Uncompahgre and its tribu-
MOUNTAIN ROADS
31
tarics have contributed in a large degree to the suc-
cessful development of some of the best mines in
North America.
Mountain roads for heavy traffic should have a
grade not to exceed 12 per cent and a width of about
15 feet. On the typical American high-road of to-
day the cost of freighting by wagon averages 25 cents
per ton per mile;* this rate is always exceeded when
the grade is above 12 per cent; in the mountains the
rate is often ten times as much, because the loads
pulled up the weary zig-zags are small compared to
the horse-power employed. Thus, with four animals,
averaging 1,250 pounds apiece, a load of 6,000 pounds,
distributed between the wagon and its contents, can
be handled along an average mountain road at the
rate of V/i miles per hour. When the gradient ex-
ceeds 12 per cent it is more economical to pack, that
is, to transport material by loading it upon mules or
burros. The average cost of this method of transport
is from 75 cents to $1 per ton-mile when there is no
return load.
We overtook a train of burros with a miscellane-
ous freight of planks, groceries, and boxes of
dynamite destined for a small mine on Mt. Potosi;
these, with bulky packages that hid their ears and left
only a view of active extremities, looked at a distance
for all tlie world like a migrating colony of Brob-
dingnagian ants.
' Mr. James W. Abbot* tells me that on European roads the cost
ranges from 6 to 13c. per ton-mile, with an average of about 10 cents.
22 ACROSS THE SAN JUAN MOUNTAINS
AdvancinfT carefully along the inside of the road,
the outer parapet of which stood sheer over a pre-
cipitous cliff, we hurried our horses past the burro
train and soon covered the six miles between Ouray
and the Camp Bird mill, where Mr. W. J. Cox, the man-
ager, gave us every facility for inspection. The mill
contains 60 stamps, weighing 850 pounds, with a drop
of 6 to 8 inches, made 100 times per minute, and a
resulting crushing capacity of 180 to 190 tons per day.
The pulp passes through cloth screens of 26 mesh and
No. 29 wire. It is then discharged upon silver-plated
copper tables, which are the full width of the mortar,
54 inches, and have a length of 16 feet. The pulp
then proceeds through classifiers, wliich distribute it
among the concentrators, namely, Wilfley tables and
Frue vanners. The coarse material goes to vanners
that have corrugated belts, the finer pulp goes to the
plain belted vanners, and the slime passes on to the
Wilfley t :>' les. Experiments were bring made in
the use ■ a 5-ft. Huntington mill for re-grinding
the coarser sand. This is likely to prove suggestive.
The tailing is delivered to the cyanide plant, and is
pumped into vats having a capacity of 275 tons apiece,
wliere it undergoes solution for nine days. Tests
were being made by Mr. Godfrey Doveton, who had
charge of the cyanidation, with a view to determining
whether the Johnson tllter-press cannot be advan-
tageou^.ly employed in the treatment of the slime that
overflows from the vats, at present the press is only
used in connection with the precipitate from the zinc-
I ■ ■!
i I (
THE CAMP BIRD MILL
23
boxes. In Western Australia the large filter-presses
have a capacity up to six tons apiece, with a tendency
to increase. They were found to expedite the treat-
ment of slime and to economize water. All experi-
ments made in this direction should be useful because
they point to a great economy of time and labor.
The Camp Bird ore is one of the most docile.
The total extraction of gold is fully, sometimes more
than, 90 per cent of the assay-returns from the crude
ore. The latter carried about two ounces of gold per
ton at the time of our visit; the concentrate represents
about 10 per cent in weight and 20 per cent of the
value of the original ore, it contains 9 to 127^
lead, 12 to 15% zinc, 14 to I67i> iron, and
20 to 22% silica (as quartz). It also carries
from 2/j to 4 oz. gold and from 11 to 15 oz. silver per
ton. This product is sacked and sent on mule-back
to Ouray, the charge for transport being $2.50 per
ton, for the six miles of down grade. Coal is brought
up as return freight at a cost of $4 per ton. The con-
centrate is then sent over the range by way of the
Marshall Pass, to the Denver smelters, 388 miles dis-
tant, at a cost for transport, of $7.50 per ton and a
charge, for treatment, of $7 > $8 per ton. The bul-
lion, resulting from amalgamation and cyanidation,
is sent under escort every day to Ouray, whence it is
forwarded through an express company to the mint
at Denver.'"
"Since the d.itc referred to. an excellent account of the Camp Bird
•nill and mine has been prepared by Messrs. Purington. Doveton, and
Woods. See Transactions American Inr'-tute of Mining Engineers, 1902.
!'i
lii;-
rl'
(■ i
I.,
i •
24
ACROSS THE SAN JUAN MOUNTAINS
After partaking of Mr. Cox's hospitality we
mounted again and began tlie ascent to the Camp
Bird mine in Iniogene basin. As we surmounted the
first rise we found ourselves in a wide amphitheatre
of serrated ridgos with a broad gap in the direction
whence we had come. Looking backward down
Canyon creek, one could not fail to observe the fact
of a succession of geological formations, on account
of the variations in the color of the rocks. The road
from Ouray first cuts through a gray ridge of S'lurian
limestone, then passes over reddish beds of Upper
Carboniferous lime and shale, which, in turn, are un-
conformably overlain by the nearly horizontal beds of
a Tertiary conglomerate that has a wide extent
throughout the adjoining mining district of Telluride.
This conglomerate, known as the Telluride formation,
has a particular interest because it lies at the
base of a great series of fragmental volcanic rocks
(chiefly andesite-brec^ia) Prifl lav flows that enclose
the majority of the important mines of the region.
This is called the San Juan formation. The road
intersects the base of the series a short distance below
the Camp Bird mill at about 0.100 feet above sea-level,
as is shown by the accompanying i)hotograph. where
J B marks the line of separation between the two
formation- (the San Juan and the Telluride). Our
trail continued to pass over successive layers of the
breccia and its intercalated flows of lava until we
reached the summit of the range, at 13,800 feet. When
a mine is situated in this country of andesitic breccia
l^il
If if '• if I
i
[i
i
h
I ' . n
I ll?i
I
i.:'ii'
f:".t
I i
H' 1 I
iifi
r
1
'
'
i' ik ■ ■
i
f f
i i '
' i
1 1
il
1 •
r
,i^
I iiK Kkafmk Mll.I.S. NK.\k Olkav
;■
i flHHFii
J SKJHHi '
III '
ii: ? :
1
9^Hlli
1
i ~W'MiMS^\ ^-
if^^^^HB
i
i I
It
I; I
II' Hi
TiiK CkK>r iiK riiK Rani.k ami hik L'l'PtK Wokkini.s of hie
ViK(iiNius Mine
*• I V.
A GEOLOGICAL SECTION
25
the distance separating the deepest workings from
the sedimentary rocks at the base of the San Juan
ormation becomes a matter of practical importance,
because experience warrants the expectation that an
impoverishment will be encountered when the vein
passes out of the volcanic series. The Camp Bird
lower adit, for example, is about 2,100 feet above the
SECTION ALONG UNCOMPAHGRC CREE.K
Fig. S.
Telluride formation, so that there is plenty of room
for further downward development. A generalized
section of the geology and topography is given in the
accompanying sketch, which I have borrowed from
Mr. H. A. Titcomb's article in the Columbia School
of Mines Quarterly, of November, 1902. In this
sketch the name 'San Miguel conglomerate' appears,
26
ACROSS THE SAN JUAN MOUNTAIN^
■
.fl
i 'M
(Ml
r- I
ri
for it was the term originally given b; nitman
Cross to the 'Telluride formation.' The old name was
surrendered because of prior use by Texas geologists.
So the name of the town replaced that of the county.
The Virginius, a neighboring mine, has an adit
— the Revenue tunnel — which strikes the vein at a
point 2,400 feet below the outcrop and 10,800 feet
above sea-level. The conglomerate is supposed to be
about 1.000 feet deeper. A shaft has proved the vein
for 900 feet below the adit, so that the total explora-
tion on the vein extends for a vertical height of 3,300
feet, which is *^]ie deepest development attained by
any mine in Colorado. The Virginius vein is remark-
able in other respects also. It has been worked for
more than twenty years. For the first 400 feet in
depth the vein was stoped continuously, although its
width only ranged between a finger and a hand's
breadth. The ore was chiefly gray copper (argenti-
ferous fahlerz) and averaged 400 to 600 ounces of
silver per ton. At about 1,200 feet from the surface,
the shaft, which followed the vein, entered a poor
zone that extended for 300 feet further. At the
level of the Revenue adit" another poor zone, about
150 feet thick, was encountered. The new vertical
shaft, sunk from the adit, has found good ore, 30
inches wide, at 550 feet. The Virginius, by the way,
" It is a pity that the word 'tunnel' is so often misapplied. In the
above case, and ordinarily in mining, the word 'adit' should be used. A
tunnel is a gallery or working that reaches from daylight to daylight,
like a railroad tunnel. A main cross-cut or level that connects a mine
with daylight is an 'adit.'
t r
THE VIRGINIUS MINE
V
has a large electrical equipment, which operates both
mine and mill. The motor cars used for underground
traction are remarkable in taking the high pressure
of 800 to 900 volts from a bare wire placed about the
height of a man's head. The power is generated
from a succession of Pelton wheels, which use the
water of Canyon creek. They present an interesting
feature in the fact that the nozzles are worn out in
ten days by the action of sand at high velocity, which
is the consequence of using a stream charged with
tailing from a mill.
1. Rhyolite and Andcsite. 2. San Juan Breccia.
3. Tellur.de Confftomerite. 4. Shale and Sandstone.
Map of Teixuride District, Colorado.
After U. S. Geological Survey.
i;l
I'l'i
Chapter 4
THE CAMP BIRD MINE— STORY OF ITS DISCOVERY
BY THOMAS F. WALSH — ON THE TOP OF THE
RANGE.
PON arrival at the Camp Bird,
the superintendent, Mr. WiUiam
Beaton, piloted our party
through a portion of the work-
ings. Both F. L. Ransome and
^1 C. W. Purington have recently
described this lode in detail."
A production, up to date, of
about $7,500,o-}0 places the Camp Bird among the
great mines of Colorado. It is also interesting as
having been until lately the property of the man
who opened it up, namely, Thomas F. Walsh.
The history of the discovery of this celebrated
mine is curious. The only outcrop of the vein for
several thousand feet is in a small gully right at the
head of Imogene basin. A claim was located on
this outcrop in 1877, but nothing further was done
because no ore of any value was exposed at this
point. William Weston and George Barber, who
were the owners, made a proposal to H. W. Reed and
Caleb Reed that if they would run a cross-cut into
the mountain, so as to cut the vein at about a depth
" liuUctin No. 182. United States Geological Survey, pp. 89-90 and
200-204, and Transactions American Institute of Mining Engineerf, May,
1902.
HOW THE CAMP BIRD WAS FOUND
29
of 150 feet, they could have the option of locating
a new claim on whichever side of the cross-cut they
chose. The cross-cut was run, and in due course
intersected the vein. The Reed brothers drove 50
feet to the west and took up a claim on that side.
This was then patented under the name of the Una
claim. On the eastern side the Gertrude claim was
pegged out by Weston and Barber, who, later on,
sold it to the Allied Mines Company. This was in
1878. Subsequently the company extended a drift
for 40 feet into the Gertrude ground, but found no
ore of any value; later still, another 10 feet was
driven, so as to make the distance 50 feet, and thus
qualify for patent. This was in 1884. The ore in
the last 10 feet was not assayed because the work
was only done to fulfill legal requirements and the
first 40 feet of the drift had yielded no pay-ore. But
as a matter of fact the drift had, in the last two or
three feet, broken into rich ore; it remained there
undetected until 1896, when Walsh broke some sam-
ples and had them assayed, thereby taking the de-
cisive step toward becoming a millionaire. Moral:
Never fail to test the ore of a drift that is penetrating
into new ground, and never assume that ore is poor
because it looks like ore you know to be poor.
The rest of the story is well known. Walsh was
an experienced miner who had met with some success
both at Leadville and Rico. In 1896 he was manager
of the smelter erected at Silverton lor the treatment
of the ores sent down from Red Mountain by the
bDI ii^
30
ACROSS TIH^, SAN JLAN MOUNTAINS
Yankee Cirl and Tiuston mines. Walsli ha 1, in 1894,
nrja^anized the company that pui up 'his plant. In the
search for silicions ores he investi.u^ated the mines of
the surroutuiing country, not only those in operation,
hut also the ahandoned prospects. He acquired the
Hidden Treasure mine, in Itnosene hasin; this was
a low-fT^rade silver-lead property, which has never
done much. In July, 1896, he went to see how work
was goine^ on at the Hidden Treasure, and incident-
ally he n *iced some pieces of pink spar amid the
rock-frasi"cnts scattered at the foot of the cliffs
that form t'b upper limits of Imo,c:ene hasin. This
pink spar he took to be lluorite, and because it re-
minded him of Cripple Creek, where also he had
mined with some success, he made a mental note of
the occurrence. In the following September he re-
visited the locality and climbed up into the old Ger-
trude adit, from which he inferred the pink spar to
have come. It was rhodochrosite; but no matter.
It led him to take samples at tlu breast of the east
drift. They were sent at once to Ouray to be as-
sayed. The returns gave several ounces of gold per
ton. More samples were taken and sent to Leadville
for assay. These results were confirmatory, so he
went to work quietly and began the steady consolida-
tion of the adjoining property. Mr. Walsh's success
was the reward following many years of most ener-
getic search, a search backed by unusual experience
in mining and extending over a large area that
contained a great number of deserted old workings
»3aKf?*^S7.#
ON THE SUMMIT
3'
■A :
likely to prove remunerative under new economic
conditions.
The main level of the Camp Bird is now over a
mile in length, so that when we emerged from under-
ground it became necessary to make haste in order
to cross the range before dark. Ouray is 7,806 feet
above sea-level, the No. 2 level of the Camp Bird is
at 11,510 feet, and the place where the trail crosses
ihe divide is at an altitude of about 13,800 feet. The
trail is a good one in summer, so that we did not re-
quire to lead our horses save in the steepest portions
of the rise and in the abrupt descent on the other side.
When we attained the summit a halt was called
while we surveyevl the splendid panorama of moun-
tains that lay outspread on either hand. Looking
back over the course we had traveled we could see
the shadows hastening to cover the valley of Canyon
creek and the sheltered corner among the hills where
Ouray lay concealed; in the far northeast the dark
mass of the Uncompahgre plateau loomed purple in
the fading light. Looking the other way, the grim
desolation of time-worn summits and crumbling
crags reached down into the gloomy gorge of the
San Miguel, which suddenly broadened into the sun-
lit valley of Telluride, checkered with cultivation and
bright with the gleam of blue water. Beyond were
green foothills, out of which arose the sculptured
mass of Mt. Wilson, silhouetted against the settmg
sun, and further still, northwestward, rim upon rim
of far-ofif hills fading into the bourne of distant Utah,
:| ^.' ,
* r
1
(T^of Ur 5
MILLS AND TRAMWAYS OF TELLURIDE-OPERA-
TIONS AT A HIGH ALTITUDE— SNOVVSLIDES AND
THEIR TRAGEDIES.
HE descent to Telluride was
^"?^ tedious, for it meant leading our
horses most of the way; and
some horses are particularly
slow to be led, however willing
to be ridden; besides, the drop
from the top of the range to the
valley i^ just five thousand feet
in the course of five miles. All the way down we
passed mines and mills; of the latter, the new Tom-
boy mill in Savage basin loomed conspicuous through
the dusk.
At first sight it seems curious to build a large mill
at an altitude of nearly 12,000 feet, instead of choos-
ing a site in the valley and transporting the product
of the mine over an aerial tramway. This is a much-
mooted question. As a rule the valley site is prefer-
able, by reason of the availability of a water supply,
the greater cheapness of fuel for power and heating
purposes, the nearness to a base of supplies, the facil-
ity that the tramway itself gives for transmitting
materials up to the mine, the more kindly conditions
of living for workmen, etc. If water can be secured
'i?
'V, ->-
TRAMWAYS AT HIGH ALTITUDES
33
the erection of a mill close to the inine itself will save
tlie cost of a tramway, that is, an amount ranging, say,
from $20,000 to $50,000; but the water-supply of the
high ahitudes is so closely dependent upon melting
snows as to be uncertain, unless a reservoir or natural
lake aflfords a chance for storage. Of course, if the
mill i- at t!u mine, the concentrate has to meet the
cost of carriage to the valley and this can be, in part,
set ofT as against the expense of tramming the ore
itself to the mill, if situated at a lower level. The
Tomboy pays ^2.75 per ton for packing concentrate
.roin the mill to the '-- -ul of the valley, at Pandora,
and as the ore yields c ,. 3 to 12 per cent of concen-
trate this cost represents . bout 25 cents per ton of
crude ore. The item of fuel for motive power is elim-
inated by the electrical transmission of power. Black-
smith coal is carried by the pack-train to the Tomboy
at a cost of $8 per ton, an amount one-half of which
represents the expense of transport. The mill and
othtr buildings arc heated by steam; in some cases
by low-pressure boilers, in others by high-pressure
boilers with reducing valves. In summer 40 tons of
coal are consumed per month; in winter, 200 tons
are consumed per month. Coal costs an average of
$10 per ton, delivered at the mine. Water for milling
piirpo'^cs is obtained from Lake Ptarmigan by a pipe-
line one and three-quarter miles long." The lake is
tiv- 'll™-.''"f "^"^u *"'' ". ^"'"- P'P"^' ""^'""^ " '■•educed to 4 inches at
( .i.nm.t; from the summit to the mill it is reduced, gradually, to 2'A
u -i^rr , 'fM„"T ='"i°"'^.'' J^'^ I am indebted to Mr. John Herron. the
manager ot the Tomboy mme.
li
!f
if
1/
41
'.'I,'
34
ACROSS THE SAN JUAN MOUNTAINS
■ , •);
1
just over the range and only 350 feet below the crest,
so that light pumps serve the purpose. These are
operated by electricity, which is bought from a large
power company in the valley, at the rate of $80 per
horse-power per annum. The Smuggler Union mine,
which has its own generating plant, pays only $35 to
$40 per h. p. per annum, but as against this, of course,
are offset the interest and redemption of the capital
used for an expensive installation.
On the whole, therefore, it may be said that the
comparison of conditions affecting the operation of
a mill in the valley and that of a mill at the mine is
without decisive result and depends entirely upon
local factors. One of these is the ability to secure a
good mill-site at a reasonable price. Another pos-
sible factor is the snowslide. To a stranger the inter-
ruption and damage from this source would seem to
present a very serious obstacle to the use of a tram-
way. It does, but to the same extent it affects all the
operations in a precipitous snowy mountain region.
Last spring'* the Smuggler-Union tramway was
stopped for several weeks in consequence of the dam-
age done by a slide, and during the same season the
Liberty Bell mine-buildings were swept away, so that
the mill was idle for four months. In the latter case
18 lives were lost, and the majority of these belonged
to rescue parties that set out to the aid of those who
were caught by the first slide. Successive rushes of
snow entombed the rescuers.
"That is, in 1902.
I
SNOWSLIDES AND THEIR EFFECTS
35
The snowslides that bring devastation to the
mines of southwestern Colorado represent a recur-
rent peril, for they are at work each spring with
variable intensity. Of all evidences of Nature's
power there is none so feared by the miner as this,
'the thunderbolt of snow.' After the winter snows
have fallen and by successive thaws and frosts have
become packed, there comes, during the period mark-
ing the end of winter, a heavy snowfall, which, set-
tling and accumulating upon the hardened surface
of the earlier precipitation, is ready to be launched
down the steep slopes of the mountains with all the
suddenness of a thunderbolt and all the confusing ter-
rors of a whirlwind. A slight movement may disturb
the uneasy equilibrium; even a mountaineer's foot-
fall may cause a huge mass of snow to become de-
tached. In southwestern Colorado, where the moun-
tain slopes are steep and but poorly protected by
forests, there are more people killed each year from
snowslides than in Switzerland, although the man of
leisure who risks his life climbing the Swiss heights
usually receives more mention in the daily press than
the miners and other humble individuals that lose
their lives in the San Juan while going to and from
their labor.
The destructiveness of a snowslide must be seen
to be appreciated; buildings and tramways are as
toys before its fierce oncoming and men in the path
of its descent are as straws in a whirlwind. In fact,
much of the damage is due to the vacuum caused 'by
■ V
1^3
|K:|
U.I ^
III
l! ^
ii!
M
' ■
.. '■>. I
36
ACROSS THE SAN JUAN MOUNTAINS
the rapid motion of a mass of snow and the cyclonic
disturbance that follows in its wake. I have often
watched a snowslide descending a neighboring ravine,
when myself out of all danger. The thunder of its
tempestuous descent first attracts attention, and
then one sees the mass of snow gathering underlying
rocks, uprooting trees, amid a quickly gathering mist
of snow particles drawn fiercely by the whirlwind in
the rear. The rushing mass will not stop at the bot-
tom of the slope, but its momentum will carry it some
distance up the opposite declivity, while all the forest
trembles and the air is darkened with a snow mist.
Ouray, Silverton, Telluride, and Creede— all in the
region formerly known as 'the silvery San Juan,' but
now identified chiefly with profitable gold mining-
are localities where snowslides are of yearly occur-
rence. One of the worst seasons in this regard was
the spring of 1884, when a series of slides came down
into the canon of the Animas, below Silverton, so
as to blockade the Rio Grande railroad to Durango.
In 90 days only two provision trains managed to get
through; for this was in the days before the rotary
plough. Nowadays such prolonged interruption to
traffic is unknown. In March, 1902, a- -ady
related, 18 men were killed at the Libert> ^ne,
above Telluride; the mill buildings were s ^way
and the tramway was severely injured. I i-- then
the management of the Liberty Bell has built a V-
shaped crib-work of solid timbers, filled with rock,
in the path of the slide that did this damage. Their
,'.!
s
!/■.
■T.
AM
v&
' ^ u
r
^ra
|K 3a
^'- - "^Al - -^
1 ill iMWli*
1 «*^-
f - 1
m
t f- «
SNOWSLIDES
37
foresight was rewarded during the spring of 1906,
for the snow broke away as before, but the slide was
divided by this obstacle and did comparatively little
harm. The slide that smashed the Camp Bird mill
is called the United States, because it annually de-
scends in a ravine past an old mine of that name.
Snowslides usually follow a line of destruction
marked out by them in previous years; this path is
indicated by the removal of trees, forming a lane
through the forest; it is also marked by the accumu-
lation of debris, and by piles of snow that survive
successive summers. The United States slide comes
down a steep slope, it crosses the road to the mine,
and descends into the valley traversed by the tram-
way, the towers of which are protected by a timber
cribbing. The Camp Bird mill is a little over half a
mile away and had never been visited by this slide.
Above the mill are steep hillsides covered with pine,
which were considered to indicate immunity from
such danger. In 1906 the mass of snow and the ve-
locity of it were such as to carry the slide down the
valley and over the edge of the hollow in which the
mill stands, so that the vast body of snow dashed
down the precipice and broke the mill-building like
an egg-shell. It was a similar supposed immunity
from danger that caused the Liberty Bell catastrophe;
for, of course, the buildings were erected at a spot
confidently believed to be beyond the range of any
slide.
;v'i
'JK
:
:ikr
1 ii W
Hi
! i
''
II
r ''-4
1'
, 1
r
it
1
1
■j-
f
i
if
k\k^
1
•J
C^pUr 6
DESTRUCTION OF THE CAMP BIRD MILL — THE
ASSASSINATION OF ARTHUR COLLINS — LABOR
RIOTS.
ANYON CREEK is illustrated
on the page opposite as it ap-
pears in summer looking from
the Camp Bird mill toward
Ouray; the photograph was
taken soon after our visit and
before the events of March 17,
1906. On that date a snowslide,
followed by a fire in the ruins, completely de-
stroyed the big mill shown in the rigl.t foreground
of the illustration just mentioned. The next three
pictures exhibit a scene of desolate grandeur; they
are reproduced from unusually fine photographs
given to the author by Mr. B. Kehoe. In the first, the
track of the snowslide is seen through the smoke and
steam ascending from the burning ruins; the nearly
horizontal layers of andesite breccia form tiers rend-
ered distinct by benches of snow and the serried ranks
of pine. In the distance a tall peak, rising from snow-
fields, pierces a troubled sky. It is a scene of im-
pressive desolation and amid such a theatre of nat-
ural destructiveness the surviving mill-buildings look
insignificant indeed. In the second there is a nearer
! »
^•^r»aife
^^r^'-^m^.
^
"^WBUMidkiTM
1
1
1
i
V
i-S^J
c^ijL. '• * "•.^:, ' - 11
^i^^^^^^^^^StJ^^36ir'''^'
li
<
1
i
<1
;l
In::! >
I.iMiKiM; iKiu N Canvon Ckkkk
rill' C;iiiii) liinl Mil. Huildings in the l-'orcjinmiid
^^
„^^
. ---dk-.-^tiK'^ ^ "
Vv. -
^ S^
~^ sr
<i iif
»^?'2rrv
Camp Bird Mill Burning
THE CAMP BIRD DISASTER
39
view of the burning mill; the heaped snow to the
right represents the end of the slide; the towers of
the tramway are silhouetted against the sunlit sur-
face; a few men and horses can be discerned indis-
tinctly. In the third illustration the brilliant sun-
shine throws strong shadows from the pines, so that
the left hillslope suggests a reflection in water; the
fire in the ruins has almost burnt itself out, the steam
does not obscure the view and the great peaks of the
range at the head of Imogene basin are in plain sight.
Nature, having destroyed, is smiling. In this scene
no human beings are discernible; man's insignificance
is emphasized.
The snowslide that demolished the Camp Bird
mill was typical of this form of natural destructive-
ness. The facts are these: For a number of days
the snow had fallen, so that a thick covering of new
snow lay on the smooth frozen surface of the winter.
Starting high on Mt. Hayden, the slide first upset
thirteen towers of the tramway and then, leaping over
a high cliff, it wrecked several warehouses and coal-
sheds before it struck the mill itself. Before coming
to rest, it crushed the lower story of a bunk-house,
devoted to a reading room, endangering the lives of
seven men, who were rescued comparatively unhurt.
As earlier slides on the same day had broken the
wires that transmitted electric power, the mill hap-
pened to be idle and only three men were in it. One
was unhurt, though entangled in the wreckage; a
v.i
i> i
m{
Wi
. 1 ^^ 1
1 . • !
!^
i'
'l
40
ACROSS THE SAN JUAN MOUNTAINS
second was dug out from under three feet of snow
and timbers, also only slightly bruised; the third vas
killed. The avalanche made no noise save when the
timbers of the mill cracked, but the air was quickly
laden with a mist of snow. The particular slide that
did the damage was known, that is, its path in previ-
ous springs was marked by a lane in the forest above
the mill, but it had never been known to run so far
or to be so violent; otherwise, of course, a different
mill-site would have been selected.
All of this happened on a Saturday evening; on
Tuesday morning a fire was detected in the upper
part of the boiler-house and this spread fast, so that
all that was left of the mill was soon consumed. As
the storage-tanks had been destroyed, there was no
chance to fight the fire. According to Mr. Stephen
L. Goodale, the odor of quicksilver was apparent for
several days after the event. "The am<!'i;,.im on the
battery plates was pretty thoroughly parted and the
'quick' driven off, leaving a gold plate on the copper.
In the clean-up pans most of the amalgam had been
parted, and the pold was left as a well-retorted dirty
sponge; but a little amalgam and quicksilver were
also left." *
There is only one way to avoid this danger; for
buildings, not to erect them at the foot of snowclad
slopes; and for men, not to go abroad on the moun-
tains just after a fresh snowfall, especially when it
'Mining and ScientiHc Press, April 14, 1906.
POLITICS AND LABOR
41
comes on top of a hardened surface. But even the
jjreatest care is insufficient, as we have seen, and so
long as the mountains raise their proud heads to
heaven they will occasionally shed their white man-
tles of snow, imperiling those who invade them in
quest of gold.
The stretch of country covered by Marshall and
Savage basins, and thence to the valley at Pandora,
has seen many a snowslide. A long tale of woeful
fatalities and romantic heroism could be told con-
cerning these three or four miles of mountain land.
In the cemetery at Telluride there are many large
graves enclosing the remains of groups of unfortunate
miners who were swept into eternity by 'the awful
avalanche.' Their resting places are unadorned by
showy tombstone or grandiose epitaph, but close-by
a new white marble monument attracts the spectator
to read the inscription upon its face. It tells a start-
ling story to those who can read between the lines.
In July, 1901, the management of the Smuggler
Union mine introduced the system of working by
contract, a system that results in paying a workman
according to his work, and which, therefore, is
directly opposed to the underlying principle of union-
ism, which demands an equal wage for the idle and
tlie energetic, the capable and the incapable. There
was a strike, the members of the union, for the most
pa; cfused to work, while a large proportion of
experienced miners accepted the contract system and
remained at the mine. On the 3rd of July, the eve
lii ■ !i
I <i !
4a
ACROSS THE SAN JUAN ..lOUNTAINS
C
'i • tj
I i
i .
of the Declaration of Independence, l.'ody of strik-
ers attacked 'he mine, shot indiscriminately into the
bunkhouses. offices, and other buildings, succeeding
in killing eik'ht non-union men nd in driving the re-
mainder over the range. ' this cowardly assault one
>trikcr was shot. It is In- tombst' e that so en
sificuously adorns the To luridc cemetery: upon it
tl.. re i- this inscription "Erected by the 16-to-l
\imers Union in memory of (then follows th- man's
name). Born in Koojok Worn Finland. Uied at
Sm. cjgkr, Colo., July 3, 1 >01, aged 27 years." Then
follow these noble lines oi Longfellow:
"In the world'< br >m\ field of battle,
In the Iiivoii,,. .f life.
Be not like dumb driven cattle —
Fie a hero in the strife."
I
Ke-
dfor
-.am*'
f.
This — this is tlie prostitution of poetr
mcrsiber, too, that no one has tv been puni
the murder of tlv ci»<ht miners killed on that
day, wli :e the one murderer, killed in the act, i- com
memoratel in marble and in poem!
This intolei Me outrag<' emphasizes the ce edi-
tions of affairs in ihe Telluride distri ?. There has
been ,= manly effort made by three or f \t nf ti e mine
manager to jirotect the right- property r^nd go.
citizenship, but it has bten han< a])pf.i " i r inter-
ference of political con.Niderat is. r ^ol
lins, the manager of the Smuei^iCr J? mine old
me of the receipt by him, fr- i 'h'- sec ar oi Ait
union, of a list of 'scabs,' namely, men wh" -fused
to accept the edicts of the unMn — 16-to-l uuon, if
■' I
HI*
^M-.
BIM!
IV
U fi
«&
l^SA^llli
!'i
^H;
" tr.
, 1
, I \
•' ' i
\-nm
i'!. H
1
Ikh
1
Ml
M
! I
I
■'I
FRONTIER LAWLESSNESS
43
^
you please! This list was interesting because the
names upon it could be pronounced! — that is, they
belonged to men of American and English descent,
as against the bulk of the miners in the district, who
are Austrians, Italians, Slavs, etc. Mr. Collins in-
serted a paid advertisement in each of the local papers
promising work at the mines under his charge to any
man on that list.
The above lines had just been written, on No-
vember 19, 1902, when the news of the assassination
of Arthur Collins shocked the whole profession
of which he was so honorable a member. I have
elsewhere" expressed my feeling concerning this
tragedy. It is a bitter price to pay for frontier law-
lessness and that political expediency which holds
the law iound in its slimy coils.
"The editorial on the 'Tragedy at Telluride' in the Engineering and
Mining Journal of November 29, 1902.
hi|/
|i ;§
f ill p.
chapter 7
THE SMUGGLER-UNION MINE — STRUCTURE OF
THE LODE — GEOLOGICAL CONDITIONS — VARIETY
OF MINERALS.
HE mine that was the scene of
these unhappy doings is one of
the largest in Colorado; it was
discovered in 1875, when one of
the claims, the Sheridan, was
first located. A stray occurrence
of the mineral sylvanite, the tel-
luride of gold and silver, was
the cause of the naming of the mining camp. The
lode proved remarkably persistent in richness
through the Mendota, Sheridan, Smuggler, and
Union claims, and beyond them into other mines;
it has been traced for over four miles on its strike
and it has been continuous: ■ stoped along one por-
tion for a length of 5,000 teet. The Smuggler lode
has yielded altogeher about $12,000,000. It cuts
through the crest of the range at 13,200 feet, where
it is encisfd in rhyolite; at 12,450 feet it passes into
a sheet of augite-andesite, which is 550 feet thick,
and below this it goes through the great series of
andesitic breccias that reach down to the Telluride
formation, at an altitude of 10,000 feet. The varia-
tion in geological environment h-'s not been withe
Thk SMru-.I.KR-l'.MON .\IlI.I.< AT PaMHIRA
.... -Tr'-^^
T^ ■ 71 "'^^==r"
"T^*
.f »«:
.•-■•«* '.*■
'i^:^
I
11:
'ill
}
Co.VTIMirATIOV OF PrECEPISG PHOWXiltAPM
!n tlu- House at the Left of This Illustration and at the Right of the
Upper One, Arthur L. Collins Was Assassinated
' !?■
I*-|
i^I '.
m
N 1»H
.-V
» i
I',- ■■
\SM
It . \i
i i
r
THE SMUGGLER VEIN
45
3
■XI
its effect upon the character of the vein. Mr. Collins
informed me that the payable part of the vein reaches
up to the rhyolite cap, the limit of proiuctiveness
coinciding to a remarkable degree with the base of
the rhyolite, where the vein is pinched, becom-
ing merely a persistent parting, easily discernible
even at a distance on account of the discoloration of
the encasing rock. In the rhyolite, the vein is ac-
companied by a little mud or selvage and some silver
ore, in patches," but no cellular quartz such as can
be seen lower down. This bit of evidence does not
favor the idea of a secondary enrichment of the lower
orebodies by means of the removal of the precious
metals in the uppermost portions of the vein. In the
augite-andesite the bonanza orebodies occur, the
richest masses of silver ore coinciding roughly in
their distribution with certain harder, almost hori-
zontal, layers of this andesite. Similarly, in the un-
derlying breccia, which is fine-grained, the pinches
in the vein occur along nearly level lines coincidiag
with the bedding-planes of the country. Good ore
makes in zones, but oxidation reaches downward ir-
regularly, and does not coincide with enrichment.
The Smuggler vein, as the drawings will show,
is notably banded; the hanging wall is usually well
defined and carries a casing, immediately underneath
which a persistent quartz leader is generally to be
Mr, John B. Parish has since informed me that in the adjoining
ground, of the Humboldt mine, he found that these patches of ore in the
rhyolite indicated orebodies in the underlying andesite.
; i
46 ACROSS THE SAN JUAN MOUNTAINS
-X'
|,':V'| meccK cou'.rnr [^ a.u<«rt [^ ^trliockj fJ^ li/sm
Fig. 6.
si
S I
.'
i=H
THE SMUGGLER VEIN
47
. / -.'A >• 7 • ' • /./
■t^^:'
Fig. ".
'(
^ I
.1
M
«
(I I
48
ACROSS THE SAN JUAN MOUNTAINS
seen. This leader is the first part of the vein to show
oxidation. The footwall is 'frozen' with quartz
stringers, which merge into the country. The gen-
eral structure of the vein suggests multiple fracturing
with but slight actual displacement, and a shattering
of the rock without much actual crushing. Vugs, or
cavities lined with crystals, are frequent ; they are due
to crustification, or crystalline growth, around the
sides of spaces separating pieces of broken rock.
The accompanying drawing" were made under-
ground during a visit in 1901 ; Fig. 6 represents the
back of a slope at the ninth level. On the hanging
there is a quartz seam, J J. This is usually the rich
streak ; if any free gold is to be found in the lode, it
will be found there. The quartz is white and rather
massive, with crystalline vugs. The next band, B B,
is a strip of hard country, included in the vein; the
part £ to D is also breccia, with some quartz; the
foot-wall country, D F, is full of quartz stringers that
drop into the vein; the outer country contains vugs
and some quartz. On the hanging there is a soft
shaly band, about three feet wide, which is used by
the miners as a 'shooting course,' that is, it is rec-
ognized as an easy line of fracture and separation be-
tween the ore and the rock.
Fit:;. 7, obtained in a neighboring stope. suggests
the arrangement of ore in relation to the bedding of
the breccia. The hanging-wall leader is represented
by the stringer B B. A l a casing of soft shaly
country corresponding to •; " 'shooting course,' as
THE SMUGGLER VEIN
49
described in connection with Fig. 6. D D are seams
of white quartz carrying iron-stained vugs. E E is
a quartzose band. The included country in the mid-
dle of the vein, from B to E, is mottled by brecciation
and does not contain as much quartz as is usual. The
foot-wall is hard.
The lode yields a wonderful array of fine crystals
of quartz, siderite, calcite, argentite, rhodochrosite,
gold, and silver. The transparency of most of these,
especially the quartz and the siderite, suggests an ex-
tremely slow process of crystallization. Siderite,
the carbonate of iron, occurs in handsome yellow
crystals encrusting both quartz and calcite. Calcite
was the last mineral to be precipitated, and it is
found lying upon the quartz that lines the geodes or
vugs. Rhodonite, the silicate of manganese, occurs
in irregular bands, usually on the foot-wall or else
in the main body of the pay-ore. Rhodochrosite,
the carbonate of manganese, is occasionally seen in
rose-red crystals. Gold is found in crystalline ag-
gregates forming specimens of great beauty. Wire
gold also occurs. Both the wire and the crystalline
gold have the composition of the true alloy, Au Ag."
In the upper workings, the native gold is purer.
While the lodes of the vicinity, as a rule, have the
general structure of sheeted bands of country rather
than that of large fault-fractures, it is noteworthy that
several of the poorer veins follow pronounced lines
"A 'act determined by the late Arthur L. Collins, who gave me many
of the data coiitamed in this description of the Smuggler-Union lode.
[1 r
;1I
50
ACROSS THE SAN JUAN MOUNTAINS
I?
of faulting. I measured the vertical dislocations tha'
coincide with the Contention and the AUeghenj
veins; in the first case the displacement is 58 feet am
in the second it is 21 feet. The Pandora faults th*
V ^ ^ ^
Cross-Section of The Contention Loue.
Smuggler about 50 feet." The Virginius vein ii
faulted twenty feet by a cross-vein.'* In these casei
it is the poor vein that follows the fault.
"John A. Porter. 'The Smuggler-Union Mines, Telluride, Colorado
Transactions American Institute of Mining Engineers. Vol. XXVI.
p. 452.
"C. W. Purington. 'Preliminary Reoort on tb» Mining Industrie
of the Telluride Quadrangle, Colorado,' li. S. Geological Survey, p. 837
1
(r()af>tftr S
THE CONTENTION MINE -AN AERIAL VOY\GE-
GOOD MINE MANAGEMENT.
\k
K spent a couple of days at
Telluridc, visiting the mines in
the vicinity. Two of our party
went up to the Contention mine,
and avoided a long ride over
road and trail by getting into
one of the buckets of the tram-
way, which makes a bee-line up
the mountain side. The aerial voyage was made
^)cedily and safely, if not very comfortably. In
wmter the managers of many of the properties find it
expedient tc make their trips to the mines over the
tramway, and in spring, when the deadly snowslide
may launch itself down the mountain at any time, it
IS much safer to travel in the air, not because the tram
i^ always immune from this peril, but because of the
shorter time to which one is exposed to danger in
making the journey in a bucket, as compared to
floundering painfully on horseback or toiling patiently
uphill on snowshoes.
The Contention is an interesting lode because it
IS productive of gohl ore in a Tertiary conglomerate,
not m the form of a bed of conglomerate impreg-
' I'?
■i i
U i I
S»
ACROSS THE SAN JUAN MOUNTAINS
nated with gold," but a nearly vertical vein-fracture
cutting through a nearly horizontal formation and
passing above this conglomerate into the andesite-
breccia series and btlow the conglomerate into sand-
stones of the Jurassic. This is an example of the
great diversity of geological environment that dis-
tinguishes the Telluride district; within a small area
productive gold and silver veins have been worked
not only in the Tertiary volcanics and the Tertiary
conglomerate underneath them, but also in Jurassic
limestone (the Sawpit mines) and in Triassic sand-
stone (the Allegheny). This, however, is a subject
too wide for more than incidental reference.
The photograph of the Smuggler-Union tram-
way illustrates the usefulness of this form of trans-
port for sending supplies of all sorts to the mines at
high altitudes. Timbers, lumber, coal, food, and
tools are put into the buckets and, when neces ry,
a couple of buckets arc spaced so as to carry the U 'i
timbers or pieces of lumber. But besides this con-
structive engineering, the photograph referred "o also
affords a natural geological section. On the iace ol
the cliffs overlooking Pandora it is possible to trace
several successive geological formations. Thus J A
represents the base of the series of bedded tuffs and
breccias called the San Juan formation; then (dowr
to C C) comes the Telluride conglomerate, and under
it are the two layers of white sandstone separated bj
a dark band of limestone, constituting the La Plata
" Such as the conglomerate beds of the Witwatersrand, for example.
^mmmmk
fiTJ
,#^
<»^\« ?
I
nflll
f ^^' 1
11
W/'m M
'Ij
' ' I
i 3
> I
f >•
Mar^hm.i. Mamn
TIk' Sluriil.iii. MiiiilMt.i. anil riiiim Mine-
\t
GOOD MANAGEMENT 53
formation; still lower, along B B, the red grits and
sandstones of the Dolores formation can be followed
along the face of the cliff. Between the Telluride
conglomerate and the underlying succession of sedi-
ments there is an unconformity, which can be seen
by an observer standing on the trail that ascends the
opposite slope.
The big mines of the Telluride district afford
examples of good management and the close econ-
omy that goes with such management. During the
past fiscal year the Tomboy treated 85,726 tons of ore
the average yield ^l which was $9.98 and the aver-
age cost per ton, $5.85. With the help of the new
mill, the costs are expected to be brought down to
$5.50. The Liberty Bell mine, for the year ending
September 30, 1902, despite snowslides and other un-
foreseen delays, handled 67,439 tons for a yield of
$7.15 per ton, at a total working cost of $5.53 per ton-
while the Smuggler-Union, on a larger tonnage, has
brought the total expenses to just under $4 per ton.
In 1902 the average mining costs were $2.90 and mill-
■nj? expenses $0.90 for 92,917 tons. Summer costs
were better than those in winter; for instance in
April, 1902, the mining cost was $2.81 and the milling
$0.74. foi 12,979 tons. The figures for mining include
expenses up to delivery of ore at the dump.
In referring to good management, it will not be
out of place to mention the action of the manager of
the lomb^y mine, who, when the old mine had evi-
dently become exhausted, was enterprising enough
H
h^
54 ACROSS THE SAN JUAN MOUNTAINS
to secure options on adjoining ground, at that time
giving promise of a good thing. Mr. Herron bought
the Argentine for his company and thereby put the
Tomboy on its feet again. In his negotiations he
was supported by his directors, and the result is the
possession of a mine that has made the shares of the
company more valuable than they were at the time
of its organization. Mr. Herron acted for the direc-
tors, the directors acted for the shareholders, and
although the transaction was a large one the share-
holders were debited only with a bonus of $10,000,
which was given by the company to the mine man-
ager in recognition of his services. It is an incident
worthy of record and does honor to all concerned.
If managers and directors of mining companies al-
ways took such a proper view of their duties, the
industry of mining would gain thereby.
A Fallt-Vein I'alltku.
; V
= -1
5 =i
- W3 r-
j - a
»!|%i
U
W' ^ ■M-1
f' -f
til ^ lit L
1
iH jm
■■ 1
■1 1 ^^1
I:
ft
w ■'^
- a
(ri>af Ur 9
ON THE WAY TO SILVERTON — THE BRIDAL VEIL
FALLS — FINE GEOLOGICAL SECTION — QPHIR —
THE RED MOUNTAINS.
N the 8th of September we
started for Silverton, We took
he recurrent zig-zag of the
iiridal V^eil trail, and in an hour
reached the top of the waterfall,
.v'hose filmy traceries had origi-
nated the name. The beauty of
the waiTfall is gone, a sacrifice
to ulih.arian engineering, which has taken the water
to supply power to the Smuggler-Union mill. The
pipe-line climbs to the place where once the rivulet
flung itself into space, and the penstock stands where
it paused for breath before its leap into the sunlit
ravine. As we halted at the head of the trail, the San
Miguel valley lay outspread with panoramic spa-
ciousness.
Nearly ho-'i/ontal lines of differently colored
rocks in ordered >uccession gave the suggestion of
long-continued natural forces building up the super-
structure out of which the sculpturing hand of Time
had chiseled the great array of mountain peaks that
rose against the cloudless skies. Emerson has said
somewhere that we ought to re«^ct "the nalurlang-
samkcU which hardens the rwfcy m a million years, and
imnm'
If .
56
ACROSS THE SAN JUAN MOUNTAINS
< \'
■
works in durations in which Alps and Andes come
and go as rainbows." It is restful to contemplate
this patient operation of natural forces in contrast
to the unresting eagerness of man- —a nervous energy
nowhere more marked than among the mines and
mills which lie under the shadows of these very moun-
tains. Such contemplation should conduce to equa-
nimity. I think it does. The records of the geologi-
cal societies show that geologists, as a rule, live long.
Above the valley rise the short slopes of red
sandstones of the Trias, surmounted by the white line
of the La Plata sandstone at the base of the Jurassic,
and above this distinct stratum, marked by a medial
layer of dark limestone, there succeed the variegated
shales and sandstones of the McElmo formation at
the top of the Jurassic ; these, being fairly soft, have a
gentle slope, partly covered by vegetation, and are
topped with the gray band of the Dakota sandstone,
at the base of the Cretaceous. All these rocks dip
down the valley westward, so that the horizontal
bedding of the overlying Telluride conglomerate
brings out the unconformity distinctly. This Terti-
ary conglomerate has a dark red color, as seen from
a distance, and it belts the base of the steep cliffs
above the valley conspicuously. It is about 400 feet
thick just below Pandora, and is covered by the vast
succession of volcanic ejectamenta, which rise tier
upon tier for a height of 3,500 feet, culminating in
serrated peaks that soar far above the uppermost
limits of vegetation.
A GEOLOGICAL PANORAMA
57
In leaving this wonderful geological section it
will not be unfitting to suggest that instructors of
geology in our schools of mines will find nowhere on
the globe a better locality wherein to bring home to
the student the relation between geology and mining,
nor will they find, with convenience, a district that
illustrates so well the working and the results of nat-
ural erosion, the operation of which Hutton and Lyell
emphasized as fundamental among the processes of
nature.
When we resumed our ride, we found ourselves
on a trail threading a pine forest. In sheltered spots
the wild flowers of summer still lingered, and the
trail crossed busy rivulets, whose voice was the only
sound disturbing the quiet of regions strangely de-
void of life. Emerging from the pines, we found our-
selves on the treeless waste above 'timber line,' and
followed an easy ascent along the bare rounded
slopes at the head of an amphitheatre of ridges. It
was a lifeless desolation, bleak and still, until sud-
denly a series of salutes rang out, to be echoed
grandly from peak to peak. These were the blasts
from mine-workings which we had not seen; they
marked the noon hour. It was time for 'croust' (lit-
erally crust), as the Cornish miners call the meal that
divides their working time: so we off-saddled beside
the first stream and ate our luncheon, while the
horses nibbled the scant dr>- grass. It seemed good
to he there under that serenely blue sky and amid an
air that made "the world seem young and life an
•jJBS "*A
58
ACROSS THE SAN JUAN MOUNTAINS
•li*
li.
epic." Those who do not know the exhilaration of
these high altitudes have not realized what perfect
vitality means.
On resuming the ascent, we were soon amid loose
slopes of debris, over which the horses went with no
more difficulty than ourselves, although the increased
rarity of the air told on them very obviously. The
trail was lost, and on choosing the lowest ridge to
the soutli, we found ourselves eventually where we
did not expect to be, that is, overlooking the little
mining town of Ophir, which I knew to be out of our
course to Silverton. We looked from a razorback
ridge far down a precipitously steep slope into a dis-
tant little green valley ; a white road threaded the cen-
tre of it, and a cluster of dwellings, like match-boxes,
seen so far, marked the settlement of Ophir. This is
not Solomon's treasure-house, but as the slanting
sunlight touched the clusters of yellow aspen upon
the lower slopes of the valley we found reason enough
for the name.
Retracing our steps into the basin from which
the ridge arose, we crossed to the eastern side, and
finding a trail, ascended d crumbling ridge, from
which we could see the ,hole complex of ranges
stretching from Red Mountain to Silverton, and far
beyond. We vere 13,200 feet above sea-level. It
did not take long to regain our wind, and shortly
the four of us were , kicking a way down the farther
side, winding in and out of ihose semi-circuhr basins
which arc so characteristic of the high country just
N'-
y i
II
^Hr^jfl^^H
A^
Ai]B|
t
K '
H.
k
II
i
hi
w\
1
m
■-'i
|! '
3 » •'
1
i' ' ^ ^
IL n
V '
w\
A GLIMPSE OF OPHIR
59
above the timber-line. It was wearisome pulling
unwilling horses over talus slopes, so we soon halted
for a breathing space and took in the view. An
amphitheatre of rugged peaks formed our back-
ground; tiers built up of successive extrusions of
andesite looked out upon a vast lifeless desolation of
gray summits and dun-colored ranges, from which
rose three flaming peaks, red as torches to anarchy.
These, the Red mountains, are a landmark through-
out the region. Their color is due to the solfataric
action of thermal waters upon the iron sulphides
disseminated through andesitic rock." At the foot
of these iron-stained ridges are situated the famous
Guston and Yankee Girl mines, which were so pro-
ductive about fifteen years ago. The origin of the lodes
is connected with that of the peculiar red summits,
in that both are traceable to the activity of acid
waters, which have precipitated rich silver minerals
on the one hand, and, on the other hand, have re-
moved the more soluble portions of the andesite,
depositing additional silica, so that the resulting
quartzose country has withstood erosion sufficiently
to survive in the form of red summits, which now
serve as beacons to the prospector."
We reached Silverton before dark.
"'Notes on Some Colorado Ore- Deposits,' by S. F. Emmons. Pro-
cceditiRs Colorado Scientific Society, Vol. II., pp. 93-99.
"This matter has been much discussed. See Theodore B. Comstock,
'The Geology and Vein Structure of Southwestern Colorado.' Trans-
actiims American Instittitc nf Mining Engineers, Vol. XV., pp. 252 264
Also S. F. Emmon.s, Vol. XVI,, p. 809, and T. B. Comstock, Vol. XVIi.,
pp. 261-264.
i ■ ■
'A, ■-
MICROCOPY DESOIUTION TEST CHART
ANSI and ISO TEST CHART No 2'
1.0
I.I
]- IIIIIM
,"■ 132
1^
140
2.2
2.0
1.8
1.25 IIIIII.4
1.6
^ APPLIED IIVI/IGE In
m-
Chapter tO
SILVERTON AND ITS EARLY HISTORY — THE FIRST
SMELTERS IN COLORADO — PIONEEF S OF INDUS-
TRY—SOME WELL KNOWN NAMES — RAPIDITY
OF DEVELOPMENT.
M
i :\\>- i
ILVERTON exhibited a condi-
tion of bustling activity; the
country tributary to it, up and
down the Animas and along its
tributary streams, has recently
undergone a good deal of that
new development which is es-
sential to the maintenance of
production in a mining district. In fact, by reason
of the energetic development, particularly of gold
mines, which has been going on ever since the fall in
the price of silver in lo93, the surrounding region is
today one of the most prosperous mining tracts
within the Rocky Mountain area.
The mountains around Silverton were first in-
vaded by the pioneers in 1871, when the Little Giant
vein was discovered by Miles T. Johnson. In 1872
an arrastre was put up, not far from the present site
of the large modern plant of the Silver Lake mine.
At that time the nearest trading station was at
Conejos, in the San Luis valley. Until 1873 the
^^-
>
^
tfl
■^:;lt
!iu
mi
i!i
/
I:
' .1 ■'!•'
if
\M 1
s
y
i
> '!ll j
|5
'•■
1
(.»
\
^ ' ,.
i
L^^MLa
T
1
■
<
\
1
i
^H
i
r
J
v|ti
i
r
^'
I i .4'
m^:
EARLY SMELTING ENTERPRISES
6i
Indians had legal control over the region, but this
was ended peaceably by the Brunot treaty.
Early on the morning of September 9 our party
of four rode down the wide main street on the way
to the Golden Fleece mine, near Lake City, about 40
miles distant. Just outside the town the road passes
the entrance to Cement creek. Here there is a new
pyritic smelter, which is close to the site of the old
Green smelter, erected by Judge Green, of Cedar
Rapids, Iowa, in 1874. The machinery for that early
metallurgical establishment came on mule-back from
Colorado Springs, over 300 miles; Colorado Springs
being at that time the terminus of the railway. The
first furnace was made of sandstone without any
lining, and Mr, John A. Porter has told me of the
advantages and disadvantages of this method of con-
struction. It had one advantage: when the silicious
portion of the charge was insufficient for a good
mixture, the side of the furnace contributed the
silica that was wanting! In 1876 the first water-
jacket used in Colorado was put into service at the
Green smelter; it was a round jacket three feet in
diameter and was made by Fraser & Chalmers, at
Chicago. The year before, in 1875, Mr. Porter had
put in a siphon-tap, suggested by his experience at
Eureka, Nevada, from which place he had come to
Silverton. This was the second siphon-tap employed
in Colorado; the first was applied at the Swansea
works, near Denver, by Ahrents. Nothing remains
of the old Green smelter save a cabin with a brick
If
'1
my
'i
il
Wf '
m
■M' u
ACROSS THE SAN JUAN MOUNTAINS
chimney, which used to be the assay-office of the
establishment. This plant was the parent of the San
Juan smelting works at Durango, erected in 1880,
and contributed a.i important share to the early
development of the surrounding region.
Local smelters such as these have helped the
exploration of the mountains. In riding across
country, as we were doing, one would occasionally
see, in contf'.st to the bright coloring of the aspens,
a black patch of ground, suggestive of the gloomy
gulf down which Plu'o snatched the fair Persephone.
These dark patches are old slag-dumps, which have
crumbled to dust, and serve as reminders of the little
smelters that preceded the large centralized estab-
lishments erected in later years at Pueblo and Denver.
The memory of these early efforts has crumbled
away, like their slags, but they are interesting not
only as small beginnings of a great industry but on
account of their human associations. They served
to train many of our best men. John A. Porter has
been mentioned in connection with the Green smelter;
at the Rico works, first built under the name of the
Grand View smelter, in 1879, such men as F. M.
Endlich, Hofman, and Arnold successively got ex-
perience and, in much later years, W. C. Brace, E. J.
Wilson, and L. D. Godshall. The early seventies in
Colorado saw the beginning of many reputations that
are now well established. Dr. Edward D. Peters is
said to have been a great champion of the reverbera-
tory in those days; he built a smelter at Dudley, at
^^^mmum.
METALLURGICAL PIONEERS
63
the foot of Mt. Bross, in 1872. The ores were rich
in silver and copper, but loaded with heavy spar, so
that although he began with only a calcining and
stone blast-furnace, 36 by 42 inches in section, with
water-cooled tuyeres, he subsequently added a re-
verberatory furnace, having a 9;^ by 15-foot hearth,
which was fired with spruce wood. The ores were
unfit for smelting by themselves, but the smelter was
operated with moderate success for two years. At
that time West was in difficulties with a matte blast-
furnace at Black Hawk, and Collom was bucking
against the impossible zinc-silver ores of Georgetown
at a little smelter just below Empire, near the forks
of Clear creek.
Colonel William L. Chandler was at Saints John,
in Summit county, just over the continental divide,
where the ore from a mine at Keystone was made
into a silicate of lead in the fusion-hearth of a roasting
reverberatory furnace. This was called 'matte' and
was treated in a low shaft-furnace; the height from
the tuyeres to the charging door being five feet.
This stuff was sent to Empire, where John Collom
was running the small shaft-furnace already men-
tioned. The treatment was a failure until H. A.
Vezin took charge of the works and produced good
silver-lead. This was early in 1872 and was the first
lead produced on a commercial scale on the Atlantic
slope of Colorado. In 1875 Anton Eilers took charge
at Saints John, but left in a short time in order to
join Billings at the Germania works at Sandy, near
i it !
f
!li
• 'I
%u
'A m I
64 ACROSS THE SAN JUAN MOUNT MNS
Salt Lake City, He was succeed d at Saints John
by Franz Fohr, who, in later years, was manager of
the Harrison Reduction Works at Leadville.
In 1874 Mather & Geist started their smelter
at Pueblo with two furnaces. This was the begin-
ning of the Pueblc melting & Refining Company.
A certain Profes? .leney at Animas Forks and a
Professor Durier ,. Animas City erected smelting
furnaces in localities as ill situated for fuel as for
ore— doomed, therefore, to point a moral and adorn
a melancholy tale.
Richard Pearce had his first experience in
Colorado in 1873, at an unsuccessful smelter erected
near Empire, on the site of Collom's old works. At
the end of 1873 this ill-fated establishment closed and
Mr. Pearce moved to Black Hawk, where Professor
N. P. Hill, not long arrived from Brown University,
was in trouble with the pyritic ores of Gilpin county.
Pearce and Hill joined forces and, under the advice of
the former, an addition was made to the plant, where-
by it became possible to treat the matte, which up to
that time had been shipped to Vivian & Sons, at
Swansea, Wales. This change of method made the
Black Hawk smelter a financial success, and led,
finally, in 1878, to the erection of the large plant at
Argo, near Denver, where, under the name of the
Boston & Colorado Smelting Company, it has since
become so well known.
James B. Grant had been recently graduated from
Freiberg when, in 1878, he built a small one-stack
FIRST SMELTERS AT LEADVILLE
6S
smelter at Leadville. Within a year this was in-
creased to eight stacks; and in 1880 Edward Eddy
and W. H. James, who owned sampling works at
Leadville, joined Mr. Grant in his smelting venture.
That pioneer establishment is gone, but it was the
parent of the Omaha & Grant Smelting & Refining
Company. Anton Eilers has been referred to
already. He was at the Germania plant from 1876
to 1879; in the spring of 1879 he started grading for
the Arkansas Valley smelter, which was blown in on
May 20 of that year.
In these early efforts there is a personal equa-
tion and a human interest lacking in the larger under-
takings of later days, because they represented the
skill, hopefulness, and energy of individual young
men, many of whom have proved to be masters of
the metallurgical art. While it must be amusing to
those who are accustomed to the more patient prog-
ress of older countries to read of a period within the
memory of active men as being 'historical,' yet, as
time is measured in a rapidly progressive mining
region like Colorado, it does indeed seem long ago.
"In a remote period of Western history, that is to
say, 30 years ago," is a sentence not without a touch
of humorous exaggeration to a European, but the
rapid achievement of a new country outsteps the slow
beat of the pendulum.
a
V i
chapter U
THE NORTH STAR AND SILVER LAKE TRAMWAYS-
SOME CLEVER ENGINEERING — COMPARISONS ■
DOUBLE AND SINGLE ROPEWAYS — EUREKA ■
VETERAN MINERS.
i •. •<
mi
S we rode along the right bank
of the Animas, we passed the
North Star mill, where John J.
Crooke employed the old Au-
gustin process, roasting silver
ore with salt and leaching the
resulting chloride with hot
water, finally p "cipitating the
silver on copper in the approved way.
Farther up we came upon the Stoiber residence,
'Waldheim,' a 30-room house, with all modern ap-
pointments, built by the former owners of the
Silver Lake mine. Just beyond, in Arastra basin,
we could see the Silver Lake mill and the tramway,
which extends in swinging lines to the mine beside
the lake at 12,250 feet above sea-level. One of the
spans of this Bleichert tram clears a distance of 2,200
feet. In a total length of 8,400 feet, the upper
division of the tram descends 2,100 feet, and has only
19 supporting towers. The lower portion — from the
old mill to the new mill — is 6,200 feet long, wi h a
m- V
A i
I i
AERIAL ROPEWAYS
67
fall of 659 feet. The tram from the Iowa mine climbs
the neighboring bluffs, and a little further up the
Animas the North Star tram reaches the river from
near the top of Sultan Mtn., a height of nearly 13,000
feet, making a descent of over 3,200 feet. Silverton
itself is situated at 9,300 feet above sea-level.
The North Star tram is two miles long, and con-
nects the mill on the right bank of the Animas with
a loading station at the entrance of an adit at 12,900
feet above sea-level. A two-bucket tramway, having
a single span of 1,950 feet, carries the ore to two
large storage bins situated in a gulch 604 feet lower
down. Each of the two buckets carries 1,300 pounds
of ore, the empty one being pulled up by the descend-
ing loaded bucket. The cable descending is 1% inch
in diameter, while the rope that carries the empties is
1 inch.
The ore-bins, just described, serve as the terminal
of a Dusedau aerial t.-amway, which goes to the mill,
two miles down the mountain, making a vertical
descent of 2,600 feet. At an altitude of 12,300 feet
the tram crosses a mountain lake with a span 1,340
feet long, and lower down there are other spans of
l.O.SO feet and 1,030 feet respectively. At the lower
end, connecting with the mill, the final span is 900
feet long, with a fall of 380 feet, crossing the Animas
river at a height of 150 feet above the water. The
tension station is midway between the mill and the
upper terminal. It is said that the gradient of the
installaf )n is such that 30 horse-power is developed;
but this power is not utilized.
!|
m
1 Mi
< li
'1
i i
1 \h
\ !
68
ACROSS THE SAN JUAN MOUNTAINS
The buckets or cars are 40 in number, and each
carries 600 pounds; they are placed at intervals of
600 feet, and travel at a speed of six feet per second.
Fifty towers are stationed along the line, the highest
being 71 feet. Two miles of steel ropes are used for
this system, the total weight of them being over 30
tons.
These numerous aerial ropes, spanning the inter-
mountain spaces like great spiders' webs, are an
important feature of mining in the San Juan region.
We had already, on the previous days of our trip, seen
the trams of the American Nettie, Bright Diamond,
Grand View, Camp Bird, Smuggler Union,
Columbia, and Liberty Bell mines, beside others, the
names of which we did not know, so that with the
group of three just referred to, near Silverton, we
had, in the aggregate, observed a good many ex-
amples of this kind of mountain engineering. Most
of the recent installations belong to the Bleichert and
Otto systems, in which the bucket is drawn over a
thick stationary cable by means of a smaller traveling
rope. The traction rope is usually from i/j to ^ inch
in diameter, v/hile the fixed cable is from 1 to 13^
inches. The older Huson and Hallidie systems, with
a single traveling rope, to which the small buckets are
attached, are nearly obsolete except for short dis-
t?nc''? and over easy contours. The need for fre-
quent supports, the consequent less substantial con-
struction, and their smaller capacity have rendered
them less desirable as a means of transporting ere
■/* -«■
llHKAKrNi; 'Ik Ml. 'rilRori.ll THK
Snow
'.Man in thk 1! tki i ' .\n
ICasikk MdiiK (IF Ik w ki.
! n
Ill : !
i
■ 1 '^^ ■ i
.' 1^"
f
irr-
^■^^N:,
'
I 'I:'! ^ i
I
Bucket Attachnu'nt
koi'K Ik \\i w.\\ s
A Loading loriniiial
Till- Webber Grip
ri
wff
tl ill T *^Ti*-V.":
^^P^^^^^^^^^^WKt?*
DETAILS OF CONSTRUCTION
69
over a rugged country. Experience now favors the
double-ropeway system in spite of a cost of installa-
tion that is 30 to 50 per cent greater than the single-
rope type, because this difference of initial expense
is soon wiped out by the cost of maintenance, which
with the Hallidie type is nearly double that demanded
by the Bleichert; moreover, in the matter • ' capacity,
it may be said that the former is limited to, say, 75
tons per day of 10 hours, while the substantial con-
struction and larger scale of the latter permit of a
capacity that ordinarily reaches from 250 to 400 tons
per day of 10 hours.
On the other hand, it is claimed" that in a tram-
way using the friction or compression grip, the rope
will stretch after it is in use, and when this occurs the
rope is reduced in diameter, so that the grip-jaws do
not hold the bucket tightly, with the result that they
slip and accidents ensue. This feature is avoided in
the Leschen tramway, which uses from two to four
bands that encircle the rope and take care of this dif-
ference in diameter within reasonable limits, for, by
tightening the bands they become as snug as the
original arrangement. When a bucket is attached
to the cable by a friction grip, it is done suddenly,
and gives the rope and the entire equipment a jerk or
jar. The operatic n consists in first moving the
bucket to the desired attaching point, and the rope,
running through the grip-jaws, wears them away,
""In correspondence received by the author from A. Leschen & Sons
Kopc Company of St. Louis.
., >m
1 ■'
\lf
70
ACROSS THE SAN JUAN MOUNTAINS
I i-.
'$ . b
h>3
and then, when the grip is closed, it receives the
sudden jar referred to.
The particular objection to a tramway using a
friction grip is that the traction rope is supported on
rollers, the latter being placed below the bucket, so
that when a bucket passes over a support, it clears
it. The bucket, however, in passing raises the trac-
tion rope about four feet. The cable then gradually
lowers after the bucket leaves the tower. The result
of this is not so apparent on a level tramway, but
where there is grade, and especially where there is a
cliff or a long span, the strain produced in the buckets
in order to raise the traction rope tO the proper height
is excessive, and will not only injure the traction
rope, but it also affects the i xed cable immediately
above. In the tramways employing a clip, such as
the Leschen type, the traction rope is supported on
sheave-wheels placed at the same relative distance
as that of the bucket to the cable. In other words,
the traction rope remains in the same vertical posi-
tion at all times, and the clip or lug is so constructed
that it passes over the sheave.
Owing to the fact that in a tramway provided
with the friction grip a bucket cannot operate around
the terminal stations while being attached to the
rope, it becomes necessary (upon detach the
bucket at the terminal) to move the bucket around
each terminal by hand. The labor required to do
this depends upon the capacity of the tramway. In
the Leschen tramway, the buckets remain attached
COST OF TRAMWAYS
71
to the traction rope when traveling around the termi-
nals. Only one man is required, and he is placed at
the loading terminal to handle the brakes and to con-
trol the flow of c.-e into the buckets. An argument
in favor of the friction-grip tram is that, by having
no lug on the rope, there is no bending of the cable
at the lug, so that the rope will last longer. This is
denied, however, it being claimed that there is less
wear on the rope near the button than there is at
any other place along the line; in fact, the clip is said
to protect the cable. The eflfect that the clip has
on the rope is said to be less than that produced by a
friction grip. The various kinds of clip or button in
use are so arranged that they can easily be moved
from one position to the other on the cable in case this
IS desired, and provision is made for turning the rope
so as to distribute the wear evenly.
The first cost of a tramway of this kind depends
upon the contour of the country traversed, and the
distance from the manufacturer who supplies the
material. In the high altitudes of the San Juan, say,
10,000 feet or over, the cost of material for an in-
stallation having a capacity of 200 tons per day of 10
hours would be about $2.10 per foot of tram-line, and
the cost of freight, plus erection, would be about
$1.15 more, so that the total cost would be about $3.25
per foot. A tramway, one mile long, having the
capacity mentioned, would entail an expenditure of
about $20,000. Actual expenditure for tramways
in this district has ranged between $2.50 and $8 per
m'^
i' m
' II
B.i-.^j. | jy- ' i
I
:i
ii
'H*'
.£<(■
A ;
«^'.
72 ACROSS THE SAN J JAN MOUNTAINS
foot ; as a rule the cheap one proves the most expen-
sive on account of the greater cost of maintenance and
repairs. Tlie Camp Bird tramway is 8,550 feet long,
with an angle station; the fall, in the length men-
tioned, is 1,840 feet, and the cost, all told, was $55,094.
It is a thorough piece of engineering work. At the
present time it is worked on two 8-hour shifts, with a
duty of 210 tons per diem. The operating cost is 17.6
cents and the maintenance 1^ cents per ton. A
large amount of material is sent to the mine, as a
back load, and the cost of handling this also is in-
cluded in the figures just quoted.
The spacing of the supporting towers is of course
governed by the contour of the ground. In this re-
ga- 1 the double-ropeway systems, with their inde-
pendent fixed cable for bucket-track, permit of a
comparatively more direct path and more uniform
movement of buckets, because the cable can be
stretched to a high tension, diminishing the deflection
in the swing of the cable. In the case of the single
ropeways, which both carry and propel the bucket, as
a high tension leads to overstraining of the rope, it is
avoided, so that there is greater dip in the cable
and need for a larger number of supports. This
is a decided drawback in a rugged mountain country.
The automatic feature of tramways is apt to be
exaggerated. For instance, it is the opinion of cer-
tain capable managers that it is a mistake to depend
too much upon gravitation, and that auxiliary steam-
power will permit of the exercise of better control over
\
AUTOMATIC FEATURES
73
the operation of the tram and the possibility, in con-
sequence, of running it at greater speed. There is no
doubt that an engine acts as a useful governor; on the
other hand, the attempts to harness a rock-breaker
to a tramway marked b> excessive gravitation have
failed, because a rock-breaker in operation is esser
tially a variable machine in its consumption of power.
On the other hand an air-compressor has not this bad
feature, and if a tram worked against an air-receiver
it would have a self-adjusting governor of a useful
kind. Most of the breakages, and much of the hard
wear and tear, are due co variations in speed and bad
control of tramways that have a difficult contour.
In this connection it is well to point out that the
modern tram owes much to the better modes of at-
taching the bucket to the rope. The use of clips or
lugs permanently fixed to the rope and employed as
attachments for the bucket was found to develop un-
even wear in the cable, and this method had the
further drawback of hindering a change in the spacing
of the buckets whenever wanted. The modern at-
tachment grips the rope wherever desired, so that the
bucket is hung at the will of ihe loader, and never
exactly at the same spot.
We continued on our way up the valley of the
Animas and soon passed through Howardsville,
which figures largely in the early reports made by
R. W. Raymond, F. M. Endlich, and other Govern-
ment officials during the 'seventies. It is now chiefly
populated by Mr. Tom Trippe. In Cunningham gulch,
Iti'" i
74 ACROSS THE SAN JUAN MOUNTAINS
%
if fi
i s
U :!'.,
Ih '
which IS close by, the andesite-breccia of the San
Juan formation comes down to the Algonkian schists
iseveral mines, such as the Highland Mary, Ureteba
and Green Mountain, exhibit this contact between
lertiary and pre-Cambrian terrains. The bes. ore
Ob ained from the lodes, which penetrate both forma-
tions is said to have come from the schist just below
the breccia; this was especially the case with the
Green Mountain vein, which had a large orebody im-
mediately under the volcanics. The next tributary
valley is Maggie gulch, where there are several younj
mines, one of which, the Ridgeway, is of importance
Ihe Ammas valley swings around to the north
and the road brings the traveler into the main street
of Eureka, the distributing point for the Sunnyside,
Mastodon, Silver Wing, and other mines that have
proved productive. Just .s Tom Trippe occupies
Howardsville, so Rasmus Hansen represents Eureka
These are among the very few of the pioneers who
are still actively at work-strong brave men, who
have crowded the romance and vicissitudes of mining
mto their own lives; men with an indomitable pluck
and a tireless activity, like that of the torrent of the
Animas, which rushes by their cabin doors, sweeping
past with a vagrant energy that heeds neither the
gladness of the radiant valley nor the gloom of the
savage gorge until, after many wanderings, it abates
Its speed and hushes its voice in the still waters of the
darkly flowing San Juan.
Cl)af>ter 12
pr2^.>t.?^x,^°^^^-™^ TABASCO MILL-BUR-
S?"colpER^ VEmr' '"'°^°^^^ ENRICHMENT
EYOND Eureka we passed the
; Silver Wing and the Tom Moore
mines, and just below Animas
Fo/ks we turned eastward and
started the ascent of Cinnamon
pass. This is at an altitude of
12,600 feet, and separates the
watershed of the Animas from
that of the Lake Fork of the Gunnison river. On
the divide is the Isolde mine, m the andesite-breccia,
also the Bon Homme, in granite, and lower down we
passed the tramway being- constructed for the Ta-
basco mine. The bright glint of a thick copper wire
bespoke a line of electrical transmission connecting
the mine and mill with a power station situated on
the farther edge of Burroughs Park. As the copper
wire caught the sunlight I was reminded of the aid
given by one metal to the other; the .ilectrical trans-
mission of the energy of -^atei has done much for
gold mining at high altitudes, where fuel for steam-
power generation entails a cost that is almost pro-
hibitive. Several successful installations have been
■ %>; ^■&if*'<J*-'i
If
76 ACROSS THE SAN JUAN MOUNTAINS
made in the Silverton district. The application of
this form of engineering was limited until recent
years. As long as the direct current only was avail-
able the transmission of power by electricity had
severe restrictions, because under that system the
practical limit was 700 volts," and it was not possible
to aiigment this by the use of transformers. Since
the introduction of the alternating current these
limitations have been swept away, and the voltage
can be raised to a degree the practical limit of which
is dependent upon the insulation of the transformers.
In practice, the voltage is usually raised so that the
power can be transmitted over a wire not smaller
than No. 5, because that size gives the lowest invest-
ment in copper. The old and the new systems of
electrical transmission can be compared by stating
that an alternating current at 2,000 volts would re-
quire only one-sixteenth of the copper that would be
required by the same current at a pressure of 500
volts transmitted by a direct current, per horse-
power, per given distance, and at a given loss. The
jost of power, as sold by the large generating com-
panies in the mountains, to the mines at timber-line
or near it, averages about $8 per horse-power per
month.
The advantage of electrical transmission of
power in place of the painful transport of fuel to the
"Although the Virginius mine uses 900 volts. This plant was erected
before the introduction of the multiphase alternating current, and the high
cost for copper wire over a four-mile line prompted the adoption of this
unusually high pressure for a direct current
ml
V
|l
M '■
■;J
8,
J 3
!
1
A>
»'' ■• '
f
1
n
J .i
A Pack-Train on the Way to the Old Hl-ndreb Mine
IN Cl-.vningham Gulch, near Silverton
-;! «
W7>W
l; <
#
f
^i<
I'' '= !i
1 i
H
t i '»
J.]
i '
:ii
■■«
1
tJifli
.1
ill
I'.
I
\r
n : H
U 5)
i 5
ii
Thk I-IKST Snow
SiJ-VER Lakk Tkail
ELECTRICAL TRANSMISSION OF POWER 77
mines above timber-line can be gauged by a look ai
the trails, which frequently afford the only means of
communication between the valleys and the mines.
This is well illustrated in the accompanying photo-
graph" of a trail to one of the Silver Lake group of
mines.
The Silver Lake installation was the first multi-
phase plant in the San Juan region. It was erected
eight years ago, and operates a great variety of ma-
chmery, such as drills, pumps, hoists, blowers,
machme-shop, etc. The line is three miles long. A
compound condensing engine has replaced water-
power because the generating station is on the rail-
road, so that coal can be delivered cheaply (it comes
from near Dnrango), while the water-pn-ver available
was both insufficient and precarious on account of
the damage to the long flume, brought about by rock-
slides, snowslides, and the other difficulties of a high
altitude subjected to violent extremes of heat and
cold.
Below the Tabasco mill we met a wagon heavily
laden with bed-plates for an engine, beariug the
name of the Colorado Iron Works; and soon after-
ward, riding through a belt of pines, we found -our-
selves in the open valley of Burroughs Park. This
district has been, during the past two years, the scene
of active prosp cting and some mining. We dis-
"^"""^ ^^ and partook of hospitalities tendered by
p. 4^'^'^"'"'"*'°'^ American Institute of Mining Engineers.. Vol. XXVI.,
I 4
IV
li'J
78 ACROSS THE SAN JUAN MOUNTAINS
1 I
ill '
Mr. George Peirce, who subsequently piloted us to
the Cleveland group of veins. These are not as yet
of economic importance, but they have characteristics
that are interesting from a scientific point of view.
They penetrate granite; the Monticello vein, which I
saw, was about one foot thick; for the first 15 feet
in depth the vein consisted of cellula*- quartz marked
by copper stains, but otherwise it was said to be
barren; lower down it became metal-bearing, and at
about 45 feet deep I found a piece of copper pyrite
coated with a gray film of chalcocite, suggestive of
secondary enrichment and reminding me of certain
experiments made by Mr. H. V. Wincheli at Butte,
in the course of which the copper of a slightly acid
solution of copper sulphate, containing also some
free sulphurous anhydride (SOO, was found after a
time to have precipitated a film of gray copper sul-
phide upon the bright facets of crystals of copper
pyrite."
In the afternoon we left this locality and rode
down Burroughs Park and nlong the Lake Fork of
the Gunnison until, in the evening, we pulled up at
the Golden Fleece mine, beside lake San Cristobal.
The road at first goes over granite covered with an
occasional patch of andesite-breccia, such as the one
in which the Champion mine is situated. Then it
cuts into the Algonkian schist and quartzite. Just
' i '' i ;
I I:
Km
I i
!>■ ,
Li
c L ". i'^Pf ""len's have been described in detail lately 'The
nTlr- 23 X\^°"^^'' ^^ "• ^' '^'"=''"="' l^^meering and Mining Jour-
nal, May 23, 1903,
*•. ',?*
LAKE SAN CRISTOBAL y^
before reaching the lake the road and stream approach
close to the contact between upturned schist and the
overlying andesite-breccia. Near the lake, decom-
posed andesite-breccia becomes the prevailing forma-
tion. The road follows the contour line of the lake
shore and afforded us a glorious canter in and out
among scattered young pines; there came glimpses of
placid water reflecting the resplendent coloring of the
""'5'?^ *1;^-^ ^'"st^ed upon the encircling hillslopes,
and the bright warm tints of clouds that caught the
sunset glow. Suddenly, in turning a corner, the road
ran among a group of cabins and other buildings the
busy aspect of which told us we were at our destina-
tion, the Golden Fleece mine.
U. S. G. S.
:%*»■■■ V'
■^v'^^Uakf VMlVtJ-UC'-^^.Sfti <*t4M -•:-!»•;,■•#--
M if > '
'11:
Chapter 13
THE GOLDEN FLEECE — A BONANZA AND ITS
VICISSITUDES — GEOLOGICAL FEATURES — THEO-
RIES OF LODE FORMATION — THE TREATMENT
OF THE ORE.
N the summer of 1896 the
Golden Fleece mine shipped
nine carloads of ore, weighing
about ten tons each, the poorest
of which netted $33,000 and the
richest $49,500. In a few
'y^^^^fw months the bonanza yielded
t^XS^^ $1,600,000. This rich ore was
characterized by petzite (Au, 257c : Ag, 41%; Te,
34%) and ruby silver (proustite) scattered through
a dark chalcedonic quartz or hornstone.
The story of this mine exemplifies the uncer-
tainties of digging for gold. In 1874 Capt. Enos T.
Hotchkiss, connected with a government surveying
party that was laying out a toll-road from Saguache
to Lake City, caught sight of the outcrop, standing
conspicuously above the hillside, and examined it.
He located it as the 'Hotchkiss' mine, and had somi-
assessment work done while he was engaged in his
survey-work in the vicinity. As far as is known, he
found no ore. A year later, when Hotchkiss had
abandoned his claim, it was re-located by George
iii ^ m
ij I
i:M
FINDING ORE
8l
vVilson and Chris Johnson, under the name of the
'Golden Fleece.' They began what is now known as
the No. 1 tunnel, but finding only little stringers of
rich ore they ceased work. Others did similar desul-
tory prospecting. O. P. Posey found a rich patch
of ore m the croppings above the No. 1 tunnel and
took out several hundred pounds, which were packed
to Del Norte and sent thence to the Pueblo smelter
Then John J. Crooke took a lease and bond; he also
extracted about $30,000 from the outcrop above No.
1 tunnel, which had been extended a little farther,
without result. This was between 1876 and 1878.*
In 1889 Charles Davis took a lease and bond; he did
a good deal of work along the high croppings, and
finally sank a shaft 30 feet deep, which struck a body
of ore yielding $40,000 in a short time. Late in that
year, 1889, George W. Peirce bought the mine for
$50,000, and commenced vigorous exploration. He
found out very soon, indeed, that Davis had extracted
all the ore in sight, and the outlook was not cheerful.
All the work up to this time had been to the north, on
the supposition that the vein had been faulted in that
direction. The new owners cross-cut south at the
No. 2 tunnel, which had been previously extended a
httle way, but had found nothing. The vein was
picked up, but not much ore was encountered at first.
They persisted, however, and within a year rich ore
was cut on No. 2, and it was traced upward until it
became easy to intercept the same body at No. 1. It
was discovered that the former owners had been
I'M
!
I
1:/
li
1
+1 >
H
\
t
I If* i
iM
I' .'^ I r
.
ACROSS THE SAN JUAN MOUNTAINS
W'Wi'
IS
bl
i
<
:ir i ^
i
TlIK Tot.I. R()Ar> BKTWEEN OCRAV AND SlUE
i
m
i'i
n
I!
M
' i H
'
r-
1 1
/
f:/
i'
ni
! h
i:r
I I
i : 1^
■ I
1 .
i 1
■ 'I
ii
i'ki
J . 1
Thk V.M.l.KV ul I (IK I'm IIMI'AHI.KK
Oiir.iN ill Miildl,. DiM.im-i-; ilu- MmmIiom' M,^;,^ R,>..iii1
THE GOLDEN FLEECE
83
withm ten feet of the main orebody of the mine, which
from that t,me. and until 1897, was highly profitable.
1 he Golden Fleece vein strikes east and west, ap-
proximately; ,t dips southward at the rate 01 33 feet
m 380 feet. In depth it flattens, so that ti.e hade for
the lower workings becomes 150 feet in 1,120 feet In
the accompanying drawing, Fig. 8. the upper work-
ings and the geological conditions are both repre-
ul \I l"""'"! penetrates fine-grained breccia and
tuffs, of the San Juan formation, until it runs abruptly
into a coarse breccia, where it scatters and ends. The
coarse breccia lies on the top of the finer series at an
angle of 28°; the diflTerence in the rate of
erosion renders the change of rock easy to recognize
at surface, even if the abrupt cessation of the con-
spicuous outcrop did not incite close observation The
outcrop makes a comb, as much as fifty feet in height
of hard smtery quartz, which, on examination, is
readily seen to be a decomposed and silicified brec-
cia, exhibiting various degrees of silicification from
he vein itself, which is almost entirelv quartz, to
the oyter country, in which the original' structure is
but slightly obscured. In this outcrop there have
been-and still are-found irregular patches of ex-
tremely rjch ore. In the underground workings it can
be seen that the vein itself follows a line of Iracture
and brecciat.on; the twice brecciated country has
been re-cemented with silicious waters, so as to form
a vuggy or cellular veinstone. Pieces of country are
to be seen enclosed within a coating of quartz The
f
$
t
.f-i'
rif.
* IP
ll.ii
M
84
ACROSS THE SAN JUAN MOUNTAINS
i ..
1^:
/;
sheeting of the rock explains the multiplicity of walls
and ore-seams that confused those who have at vari-
ous times exploited this vein.
The outcrop ceases when the vein encounters the
coarse breccia; so, also, in the underground workings
the vein itself comes to an end with a suddenness that
is, however, only comparative. The contact {-d B)
has been considered a fault ; a good deal has been said
concerning its regularity and clean-cut character.
This, however, does not, I believe, accord with the
facts. The so-called 'fault* is not a break or disloca-
tion in the rocks ; it merely marks the division between
the layers of fine-grained breccia and an overlying
formation of coarse breccia; there is no smooth plane
or wall or defined parting between these two forma-
tions, but only a sudden transition which at a distance
is more marked than near-by.
The orebody of the mine was found in a tri-
angular block of ground bounded on the one side by
this 'contact,' A B, on the other by the hillside, B D,
and along the base by the No. 3 tunnel, A D. The
outcrop was patchy and irrporerished by leaching,
the evidence of which is marked. This robbing of
the croppings probably enriched the vein a little lower
down. A branch vein, called the lima, which comes
in from the northeast, appears to have played a part
in determining the eastern or outer limits of the ore-
body.
Speculation concerning the causes that deter-
mined this occurrence of rich ore is not hampered
fi' !
THEORY OF ORE DEPOSITION
85
by too many facts. A correct explanation suffers
from the lack of them. The contact existed before
the vein was formed. The fracture, followed by the
ore, passed easily through the finer-grained rock, but
ceased abruptly when it met the beds of coarse brec-
cia, because the force of fracturing was not only in-
sufficient to overcome the resistance of the harder
fragments contained in the latter, but it must have
been dissipated by the encounter with a loose-tex-
tured body of rock, much in the way that the power
of a diamond-drill becomes wasted in passing into a
shifting mass of loose conglomerate. As a con„.-
quence, the energy of shattering was diverted along
the contact, the vein-fracture ceased, and the later ore-
depositing waters were barred from farther advance
into the coarse breccia, save as a scattering confined
to the neighborhood of the contact. At the third
level, the orebody, which here is in the fine-grained
country, was notably wider immediately at the 'con-
tact,' and in examining the outcrop of the vein I
noticed that it was difficult to decide upon the exact
line of separation between the two formations, be-
cause the mineralization extended from the fine into
the coarse breccia so as to obscure the divisional
p!ane.
The deeper levels have found some small bodies
of ore, and a good deal of money has been obtained
from isolated pockets all the way down to the main
tunnel or adit, about 700 feet below the third level.
Several larger bodies of low-grade ore have also been
lul
!■
: 11
86
ACROSS THE SAN JUAN MOUNTAINS
I I
\
encountered in the deeper workings. Exploratory
work is still going on, especially near the contact,
where the chances for finding more ore seem to be
reasonably good.
Most o^ the rich ore of the Golden Fleece mine
was shipped to the smelters, but the low-grade mill-
stuff was treated on the spot. As the valuable metals
were chiefly contained in telluride minerals (prin-
cipally petzite, but also some hessite) the treatment —
by concentration — presents features of interest. The
mill was of latest design, erected by Stearns, Roger
& Co. It consisted of rolls for crushing, Huntington
mills for re-grinding, VVilfley tables for concentration,
and a canvas plant for the treatment of slime. No
use was made of amalgamation. The Huntingtons
were provided with screens of 30 mesh, and experience
showed late*- that 20 mesh would have been better.
In treating 18,000 tons having an average assay-value
of $10.25, half of which was in gold and half in silver,
the extract! . averaged between 45 and 60%; 637o
was the best result. The concentrate contained 55 to 65
oz. silver, 1 to 3 oz. gold and 12 to 187c lead, in the
form of galena. The concentration was in the ratio of
12 to 1. It may be said that the experience with this
ore indicated conclusively that a simple mill," with
Wilfley tables and an extenc'ed canvas plant as the
principal features, would have been adequate.
"The mill was really designed for an ore containing galena and iron
pyrite, both of which proved unimportant ingrp'lients when the mine
became further developed.
Cfyxfhv 14
SLUMGULLION GULCH — LANDSLIDES — THE CAN-
NIBAL PLATEAU — A GRIM TALE — ROCK DISIN-
TEGRATION—ACTION OF FROST.
E remained for two whole days
with Mr. Peirce, and early on
the 12th of September our jour-
ney was resumed. In crossing
the valley of the Lake Fork of
the Gunnison one cannot help
noting the peculiarities of the
surface. The eastern range,
opposite the mine, is marked by a depression known
as Slumgullion gulch. As seen from No. 3 tunnel it
looks like a big landslide, the steep slopes of which
have been obscured by weathering. However caused,
it has reached down to the valley and dammed the
stream so%s to form lake San Cristobal. It is said,
by those living on the lake shore, to be still in mo-
tion and to be extending farther across the valley.
Slumgullion is commonly imputed to glacial ac-
tion, but the observeo facts do not require us to go
so far afield. Landslides, some of them of great ex-
tent, dating back to early Pleistocene time, have been
recognized and carefully studied in the Telluride and
Rico regions. They are attributed to the penetration
of water along bedding-planes and other lines of part-
i k .1
1S I
,1.
^
V i
:(l
! Ill
in
it '>.i'
w
!i M
H
H
88 ACROSS THE SAN JUAN MOUNTAINS
ing. In the case of Slumg^Uion the porosity of the
coarse layers of breccia permitted the entrance of
water, which would reach down until a less porous
stratum was encountered and then, if the dip-slope
were toward the valley, the conditions would be ripe
for a landslide. The geological conditions observed
in the Golden Fleece mine would favor such move-
ment if the bedding-planes dipped with the hillside;
they dip right into the hill, however, and as a conse-
quence the surface slopes steeply, at 30° and over.
The same geological structure if carried across to the
other side of the valley would explain the landslide of
SlumguUion. In the earlier history of these moun-
tains they were bolder than they are now, and when,
at the* close of volcanic activity, earthquakes super-
vened, then the landslides occurred on a colossal scale
and were accompanied by a shattering of t'^e rocks,
covering areas e iding over many square miles.
The ascent ui SlumguUion was easier than it
sounds, and as we filed along we were reminded by
the mention of the Cannibal plateau, rising in bleak
ruggedness to our left, of a tragedy the details of
which no human witness has truthfully told. In 1873
a party of prospectors, intending to go to Fort Gar-
land, in the San Luis valley, found their way up the
river which we had left. It was a very severe winter,
so that game was scarce ; they were verging on starva-
tion, and on their last legs. Out of the five men, one,
named Parker, survived ; he claimed that he went out
into the woods hunting and on his return o..e of his
'■S
SLUMGULLION
89
comrades, rendered mad by hunger, attacked him
with an axe, so that he had to shoot him in self-
defense. Then the other three set on him, so that he
had to kill them also. It is generally believed that
Parker killed them to get the money they are under-
stood to have carried. Game was not as scarce as he
represented ; at all events he managed to support him-
self until he worked his way out, and finally reached
Durango, where he was subsequently arrested, con-
victed, and sentenced to imprisonment for life. Two
years ago he was liberated by the then Governor of
the State. In his gruesome story he confessed to hav-
ing been compelled by hunger to eat portions of his
victims; hence the ominous name, which, like the
gloomy brow of the Cannibal plateau itself, over-
shadows the fair valley of San Cristobal.
At the top of Slumgullion gulch the road turns
eastward to Creede ; we turned northward and, pick-
ing up a trail that plunged into a pine forest, we
eventually found ourselves at the headwaters of the
Cebolla and followed it down. We were soon on a
well-beaten path— the old Ute trail, us 1 by the Indi-
ans in their migrations across the Gunnison country.
They are gone from these hills and are now huddled
on the reservation; so also the game which they
hunted ; that too has been driven away by the restless
prospector. As we rode along in single file there was
no sign of living thing for hours of travel ; we followed
the Cebolla, fringed with willows and threading nar-
row valleys overshadowed by cliflFs of architectural
I
' f
-.n
m
ii'
Ml
'
wh
go
ACROSS THE SAN JUAN MOUNTAINS
n ,
'!
^'^,'i
aspect, battlemented masses and moni'mcntal piUars,
like Egyptian pilons, among which a babbhng trout-
stream took its quiet way. The mountain flanks ap-
peared to be buih of rhyoUte and rhyolite breccia.
Occasional fragments of obsidian were found. Later
we were in a granite country.
While picking our way over the talus at the foot
of high cliffs and noting the general air of destruction
that had characterized much of the rock structure
seen during this particular morning's ride, it was im-
pressed upon the observer that frost action was the
chief agent of disintegration. To mos; people who
travel among mountains, and even to those who live
at their feet, it is often a wonder how the rocks are
broken, and when. Anyone who sleeps outdoors will
note the fall of rock-fragments during the night, and
to this fact. I think, is due the general immunity from
such danger. The patient leverage (t ihe fi.*:,. is the
chief agent in disintegrating the rocks, for, the max-
imum density of water being at 4° C. or 39° F.,
one of the most powerful of nature's silent forces
is set to work upon the water, which, having sought
out the cracks and crannies of the rocks, is in the act
of expanding. By day the temperature in the high
mountain country is raised by reason of the penetra-
tion of sunlight through the clear atmosphere, but
at the approach of right there is a sudden cold, which
is succeeded next day by another relaxation. Dur-
ing these variations of temperature the moisture in
the rock-cleavages undergoes an alternation of con-
U':
m
CATHEDRAL
91
traction and expansion, which serves as an intensely
powerful agent of disintegration.
At noon we pulled up at a spot marked in large
letters on the map as 'Cathedral' and found a solitary
log cabin with a hospitable woman in command, who
gave us dinner. Subsequently, when smoking a
soothing pipe, we could appreciate the simple gran-
deur of the granite forms, sculptured by Time and
chiseled by the heat of day and the frost of night into
buttresses and pinnacles simulating all the stern
magnificence of a Gothic ruin— of a cathedral not
made with hands, domed by the sky, and aisled with
the green of the peaceful valley.
_^ r-r— 'Sr- --!--' .-
U. S. G. S.
li
ill
it
hi
Y4 I
If i ^ 4-
4 »i iJA
'IS
t]
I :
I
1/
(I'll
j,:|J
^' i 'H
f
. 11
i '{
M
i
^\i';l
' '■!; L rJ
ii
\t)
VI' I fl
(ri)apUr 15
THE CEBOLLA HOT SPRINGS — THERMAL ACTIVITY
IN THE ROCKY MOUNTAINS — ITS RELATION TO
ORE DEPOSITS — THE GUNNISON PLATEAU.
LL of the succeeding afternoon
was spent in a comfortable ride
down the expanding valley of
the Cebolla, which now began
to exhibit cultivation, until,
with a long gallop through the
cool air of the twilight, we
reached the Hot Springs. Here
we put up over night. From a distance the patches
of white incrustation and clouds of steam told us of
our approach to this scene of thermal activity. The
links between vein-formation and hot springs which
are to be seen throughout this region are not lacking
in suggestion. The mining districts of the Rocky
Mountains are rich in hot springs. In Colorado there
are Hot Sulphur, Idaho Springs, Manitou, Canyon
City, Glenwood, Poncha, Wagon Wheel Gap, Pagosa.
Trimble Springs, Ouray, and others of less im-
portance. Similar conditions obtain in the States of
Idaho, Montana, and Utah. The occurrence of these
thermal springs, rich in alkaline and other salts, in
the midst of a productive mineral region, is not with-
out significance. Apart from their scientific aspect,
hJI
THE GUNNISON PLATEAU
93
the hot i rings jilay ; useful part in the economy of
man. "] le*. are the csort of people troubled with
ailments tt quiring ri st and change of food; to the
miners, who coait t them with rheumatism, indiges-
tion, alcoholism, and similar troubles, they are ben-
eficial, chiefly by reason of the opportunities for
cleanliness, abstinence, and a simple diet — the last,
to my mind, the especial boon of the thermal spring
resort, because the miner lives in a world of sin and
canned vegetables from which 'ranch food' and early
hours of sleep will rescue him, bringing his inner man
to a condition of normal healthiness.
Next morning, September 13, we turned east-
ward from the Cebolla valley and struck across coun-
try for Vulcan. At the foot of a high ridge we passed
the Old Lot mine, cheerfully active. The dump in-
dicated a vein carrying two or three feet of dark
quartz streaked with galena. Close to the latter oc-
casional specks of native gold could be seen — a hand-
some-looking ore. On the top of the ridge there was
aflForded an extensive view of the Gunnison plateau,
bounded to the north by the deep gorge through
which the swift Gunnison rushes, and to the south by
the bold outlines of the San Juan mountains. Look-
ing eastward the outlying summits of the Cochetopa
hills broke the sky-line, but westward the sage-clad
ridges stretched in sober gray until they faded into
the blue of farthest distance. Though tame as com-
pared to the grandly picturesque mountain-land from
which we had just emerged, this plateau yielded a
■i-:
l ■ 'i
UM
m
■4 ^
'M
!;
^H
1 '
n
1
/
L' 1
>
•
I i,
til
III!. I
■W
.'II
B
94 ACROSS THE SAN JUAN MOUNTAINS
pleasure of its own in the glorious spaciousne^^s of a
boundless horizon.
This billowy succession of rounded hills is built
up of Archean granite and Algonkian schist. We saw
several outcrops of the latter, especially in the Vulcan
district. Flows of Tertiary lava and layers of breccia
form occasional flat-topped ridges with broken edges
and tumbled slopes of debris. The occurrence of an
area of schist is an interesting feature, for although
there are oti.er stretches of these .ocks, represented
by the actinolite schist of the Arkansas valley and the
hornblende schist of the western slope of the Sangre
de Cristo, this particular rock is unusual in the min-
ing regions of Colorado, and is not regarded as a
favorable terrain for precious-metal mining, a fact
which is in striking contrast to California, South
Dakota, and other productive regions.
A Lode in Quartz-Schist. New Zealand.
s
o
'A
in
%
I.
! ;
n
i :
^
l\Ji
i
^»
I, i
In' '1
•! i'
i(
(.1
( '
IUkrdii.hs 1'akk
chapter 16
VULCAN — THE GOOD HOPE MINE -GEOLOGY OF
THE VEIN -NATIVE SULPHUR AND TELLURIUM -
ACID WATERS — THEORIES OF ORIGIN -RARE
MINERALS.
N arrival at Vulcan we pro-
ceeded at once to the Good
Hope mine, owned by Dr. Loui
Weiss and others, who invited
us most cordially to see the
workings. This we did very
gladly because the mine was
well known as having been the
source of the handsome specimens of native tellurium,
which are to be found in many mineral collections;
furthermore, I had heard of several peculiarities of
lode-structure that aroused curiosity.
The Good Hope vein penetrates a greenish-gray
sericite or hydrous mica schist, which has the greasy
feel and fine texture characteristic of that rock. It
forms part of the Algonkian series of crystalline
schists that overlie the Archean granite of the Gunni-
son plateau. The vein has an approximately east and
west strike; it dips northward, the hade being 40 feet
in 500 feet. At surface the vein has an outcrop of
heavy iron sinter, which eventually gives place under-
ground to a band of country thickly impregnated
^l
m
;ir5 a
ill
\i
\
\ '
II
. i :
J
M
w
fit '
Hmi
li
< \
i
ii
96
ACROSS THE SAN JUAN MOUNTAINS
with iron pyrite. The walls of the vein are smooth
and soft, both features being due to a parallelism with
the schistosity of the enclosing country. No selvage
or casing was noticed, but the lode-matter breaks
rather readily away from the country on account of a
blocky jointing, which, added to the fissile character
of the rock itself, makes mining operations danger-
ous unless the timbering is well attended to. The
rich ore is associated with streaks and lenses of iron-
stained schist traversed by stringers of quartz.
Native tellurium is frequently present, but the min-
eral that carries the gold has not been detected with
certainty. 1 found some spots of petzite, and it is
likely that this is one of the enriching minerals.
The accompanying sketch (Fig. 9) of the lode,
as seen at the fifth level, will illustrate its structure.
From J to B is the main pay-streak. On the hang-
ing wall there are 3 to 5 inches of quartz, usually
i.on-stained; then comes a bleached decomposed
schist carrying a little quartz throughout. It is this
white silky schist that usually carries th» telluride
minerals. The band B is soft white schist, C is three
feet wide and consists of massive granular-crystal-
line iron pyrite in finely shaded bands that reproduce
the lamination of the schist. D is another band of
bleached schist. E is similar to C, but not so solid.
The end liing country also carries a scattering of
pyrite.
In the upper levels there is evidence concerning
the origin of he vein and its contents. The occur-
i« IS 1
THE GOOD HOPE VEIN 97
rence of a body of native sulphur has been empha-
sized, practically, by its combustion to an extent that
endangered i. c mine. The adjoining ground in the
Chimney and Vulcan claims was abandoned on ac-
U! Il'.l
'''•I'l'
—LjjJJf '
Fic. 9.
count of the burning of a similar body of sulphur.
In the Good Hope there is a body of it 105 feet deep, 4
to 6 feet wide, and of a length which the o\.ners
thought it unwise to determine by further driving.
The top of the sulphur nearly coincided with the first
level, 90 feet from the surface. This substance, which
1
'7i
I ,,
1 :
f ■'!•
t
'J
lii:
M.
if' h
X
1^
1
98
ACROSS THE SAN JUAN MOUNTAINS
occurs as a grayish-yellow loosely coherent powod,
was shipped in car-load lots to the Western Chemical
Company, at Denver. It averaged 80 per cent sulphur
and also 3 to 20 dwt. of gold per ton. The water of
the mines on this vein is very acid and green in color.
It carries over 1 % copper and 1.5 % sulphuric and
sulphurous acids.
On inquiry I was given the analysis of the water
from the shaft on August 15, 1901 : Grains
per gallon.
Sodium chloride 1.82
Sodium sulphate 3-39
Calcium sulphate 4-35
Calcium carbonate 4-6i
Magnesium carbonate 6.52
Silica 0.23
Organic and volatile matter 3.67
The water contained no free sulphuric acid, or at
most a trace; there was only a trace of copper. It is
the opinion of Dr. Weiss that the sulphuric acid and
copper now found in the water of the mine come from
the adjoining Vulcan ground and are traceable to the
effects of the burning of the native sulphur, which
lasted for two weeks in the Vulcan and Mammoth-
Chimney workings. There was no acid nor copper in
the water from the Good Hope shaft until after the
fire, and it is probable that surface waters have since
then perco'ated through the Vulcan workings and
thence downward to the fifth level of the Good Hope,
which is 100 feet deeper than the V^ulcan shaft. Apart
from this fact, it is worth noting that the copper in
ku
I *.J
EXAMPLES OF VEIN STRUCTURE
'''''/.■■•rtn«--:'/-/?'-;--//''
Fic. 10.
li,
Fic. n.
00
.1
J J
Ml
J I
.il 1
:i.3
({
ii !,
loo ACROSS THE SAN JUAN MOUNTAINS
the Good Hope ore is increasing in amount with
depth, specimens of the native metal having been
found in the quartz from the lov^'cst level.
At the first level there is evidence that the vein
was shattered and that a certain part of it, at least,
served as the vent for a thermal spring of compara-
tively recent date. Fig. 10 and 11 were taken, the
first within 100 feet of the shaft and the other farther
eastward. They exhibit the shattering of a vein of
opalescent quartz and the filling of the vein-fracture
with geyserite, for a width of four or five feet. The
substance that is here termed 'geyserite' has a
specific gravity of 1.96 to 2. It is porous, with scat-
tered bits of opal within a mass of grayish-white
crumbly hard non-crystalline silica. On comparing
it with a piece of geyserite from the Yellowstone, the
identity was apparent. The banded opalescent quartz,
so abundant in the upper part of the vein, has all the
characteristics of such a substance when deposited
from thermal waters, and it occurs in the Good Hope
vein in various stages of hardness and texture. Fire-
opal is to be seen in occasional brilliant specks, and
many varieties of dark jasperoid quartz are found,
beautifully banded.
The gradation from geyserite to white sericite
schist indicates that the latter contributed part of the
material now occupying the vein-fracture, and the oc-
currence amid the silicious sinter of occasional
patches of a smooth unctuous white powder suggests
THKRMAL WATERS
lOI
remnants of the mica that characterizes the enclosing
country.
These facts point irresistibly to the activity of
thermal waters, that is, waters having a temperature
higher than the mean annual temperature at the sur-
face. Geyser action has, so Dr. Weiss tells me, been
quoted in this connection by other visitors to the
mine, but a geyser is a thermal spring that gushes"
at the surface, and in this case we have no reason to
suppose that such action occurred. Geysers are apt
to be the last resort of a perplexea geologist. The
supposition of thermal activity is based on the occur-
rence, in the vein, of substances that are actually
deposited from the hot springs in the Yellowstone
and other places.
In connection with this occurrence it is well to
refer to the evidence of vein formation at hot springs,
such as Walter H. Weed observed at Boulder, in
Montana.'" At that hydropathic establishment there
are two groups of hot springs, issuing from fractures
in the granite and having a temperature ranging
from 120° to 164°. These waters do not torm
a surface deposit of sinter, but the fissures from which
they issue are found to contain a mineral deposit.
Many of the fissures have been sealed with this de-
posit so as to form veins, the outcrops of which enable
" ^^,^^" '* "''" '"'sndic word, meaning literally a 'gusher.'
vv I. ^i"*^"' Vein Formation at Boulder Hot Springs. Montana,' by
Walter Harvey Weed, United States Geological Survey, 1900
am
Ml
I i >•; il
loa ACROSS THE SAN JUAN MOl'NTAINS
one to trace their course ac.-ss the country. The
vein-filling consists of a white or dark-gray material,
which is mainly a mixture of chalcedony and stilbite,
but also contains patches and bands of jasper, as well
as included fragments of the granitic country. The
illustrations given by Weed resemble the structure
to be seen on the first level of the Ciood Hope mine.
Opaline silica, in bands and curly layers, is seen
throughout the mass. When freshly fractured it is
usually dark-gray and very hard. The surrounding
surface shows scattered fragments of jasper, chal-
cedony, and other substances evidently derived from
these deposits. On analysis they were found to con-
tain an appreciable amount of gold, as much as 0.05
oz., and silver, as much as 0.4 oz., so that the connec-
tion between ore formation and thermal activity is
manifest. It is interesting to note that the author
does not impute the source of the heat to 'unknown
depths,' but to meteoric origin as "a part of the nor-
mal underground circulating water of the region,
heated by physical conditions giving it access to the
still hot rocks underneath.""
It would seem" that the Good Hooe vein existed
as a pyritic band in tin- schist, formed by the action of
feebly active underground waters such as, with ex-
"Cr ri7,p. 250
" 1 iie reader i'= tminded that these data were gathered during a visit
of a couple of hour^ while on a horseback reconnaissance across the coun-
try, so that the writer's explanation of the origin of tlie vein is only a
suggestion, prompted by the interesting featuies that have been briefly
sketched.
'i^,:-.. '■■>'■
hi^-
DioHiiK CuNTAtT (>N Silver Moixtain. neak Ophir
N. 'ti' Cabin iu Kiijlit Ijimit G)riur
'. n
il 1
if
t
.m
ii i.s
I ;
is
I
! <
Ull,
', :'; 1'
' t
1,
(
'1 1 P.j
!■
J'
I
> ,-
tc j:
GEOLOGIC ACTIVITY
103
trenie patience and slowness, are supposed to form
similar lodes. Long duration of time for action and
immense volume of solution compensate for feeble
chemical activity and extreme dilution. The forma-
tion of the fracture occupied by the vein and the cir-
culation of underground waters, which supervened,
may both have come in the wake of dying volcanic
energies, such as were manifested in the adjoining
region of the San Juan mountains.
At a later date, after the Good Hope vein had
been formed, it underwent a repetition of fracturing
along which more intense thermal activity had play.
A part of the vein served as a vent for a hot spring.
This shattered the pre-existing vein and led to the de-
composition of the pyrite, with the elimination of sul-
phuric acid, the formation of an iron sinter, and the
accumulation of a large mass of native sulphur. It
is also probable that the liberation of iron salts, such
as the proto-sulphate, afforded solvents for the gold,
which was re-deposited in the lower parts of the vein
so as to make valuable ore.
The Good Hope vein is rich in uncommon miner-
als. Tellurium occurs native, as a tin-white mineral
with a metallic lustre. Occasional specimens exhibit
rhombohedral prisms. It is associated with petzite,
the telluride of gold and silver, and a new mineral,
the telluride of copper." A greenish-brown mica-
"'Rickardite, A New Mineral,' bv W. E. Ford. American Journal of
Science, Vol. XV., January, 1903. this contains 40.51% copper, 59.49%
tellurium. The composition corresponds to the formula Cu.Te..
\
1 I
•f ' !
104 ACROSS THE SAN JUAN MOUNTAINS
ceous substance suggests roscoelite, a vanadium mica,
which occurs in association with telluride gold ores in
Boulder county, and at Cripple Creek, Colorado,
as well as at Kalgoorlie, Western Australia.
One specimen, secured on the occasion of our
visit to the mine, contained fine needles of
berthierite, a sulph-antimonite of iron, which bears
some resemblance to stibnite. The opal of the upper
levels is said to have been rich, especially in the
purple-tinted spots; this may have been due to a tel-
luride salt. The distribution of the tellurides, to-
gether with the native element itself, is another sug-
gestion of the instability of these compounds in
nature. As far as is known they are not characteristic
of deep mining, but are more especially distinctive of
that bonanza zone of gold lodes which is measurable
from the surface and appears to be connected in
origin with the conditions obtaining at the ground-
water level. Of course, 'deep' is a relative term, and
in this connection it refers rather to the vertical dis-
tance from the lower limit of oxidation than to the
position relative to the surface.
LI
) I
1
vi^'^
^
Cl)apUr \7
GUNNISON -THE DERELICT OF A BOOM-
CRESTED BUTTE -THE IRWIN DISTRICT AND THE
FOREST QUEEN MINE -SILVER VEIN IN SAND
STONE -ANTHRACITE COAL.
ROM Vulcan our trail took us
over the eroded stumps of
granite hills and across the river
into the level s. etch of country
over which the town of Gunni-
son spreads itself drearily and
wearily. Gunnison was a boom
town, and when the wind goes
out of a boom the wreckage is not enlivening Be-
tween 1880 and 1885 there were three smelters at
work. The combination, in the neighboring moun-
tams, of iron, coal, and precious-metal deposits won
for Gunnison the splendid title of 'a new Pittsburg.'
The town attempts to covjr an area of two miles
square, so that when you think you are in Gunnison
you are out on the prairie, and when you imagine you
are out in the country you are on a main street. In
spite of it all, Gunnison wears an aspect of resigna-
tion, as if to say 'it is better to have boomed and bust,
than never to have boomed at all.'
The next day, September 14, we started for
Crested Butte, the centre of an important coal region.
f
i 1
' M
I
i|
vw
i:.
io6 ACROSS THE SAN JUAN MOUNTAINS
The road follows the main branch of the Gunnison,
a famous trout-stream known to every follower of
Izaak Walton; the valley broadens at times into a
goodly expanse of farm-land, dotted with cheerful
homesteads. A few miles below Crested Butte the
river is flanked by mountains, among which the rhy-
olite cone of Round mountain and the basalt-capped
mass of Mt. Wilkinson are conspicuous. Finally the
traveler reaches the confiuenc" of several streams and
a wide basin, on the western edge of which the town
of Crested Butte has been built. A noble mountain,
buttressed with steep cliffs and massive as an anchor-
age for an aerial tramway to Mars, overlooks the
town from the east, and has given it the name of
Crested Butte. It is a big stock of porphyrite." On
the west and south the gentler slopes of Mt. Wheat-
stone, fringed with pines, merge with the valley, and
to the north a perspective of successive peaks in-
dicates the Ruby range. These gain height and mys-
tery as seen through the smoke from the coke-ovens
of Crested Butte, lying huddled under the long shad-
ows of evening. In the centre of the town we found
a barrack-looking building, which turned out to be
a c'ean and comfortable hostelry. Next day, the
15th, saw us on the Coal Creek road, on our way to
Irwin and Floresta. On both sides of the canon the
hillslopes were a desolation of burnt timber, a glimpse
of that destruction, through careless fires, which is
"Crested Butte Folio. U. S. Geological Survey. 'Igneous Rocks,'
by Whitman Cross.
\ [ . A
|i i
t\ i
Mt Tkk-au.i a HiGHLANn Mfadow
I
^ 1
ii
i-i
■rflMl
Mi
[Hh
1 ii
■
im.,'^
THE IRWIN DISTRICT
107
\
gradually causing the deforestation of Colorado. The
actual burning of good trees is bad enough, but the
effect of such fires on the young growth does the
more serious injury to the possibilities of a future
supply of timber from these devastated tracts of
mountain-land.
As the higher altitude was gained, the scenery
improved and became bolder. We were passing
through a porphyrite country, and the large frag-
ments that had rolled to the roadside showed hand-
some crystals of feldspar. A winding trail took us
northward from the westbound road and brought us
to the deserted hamlet of Irwin. The Irwin mining
district was active in 1880 and succeeding years. The
Forest Queen mine is credited with a production of
ever a million dollars. In 1893 the fall in the price of
silver flattened out the life of the camp, and until
lately it has remained practically deserted. Quite
recently a consolidation of a group of mines has been
effected, and there is now promise of some activity.
We visited the Ruby Chief mine, under the kind guid-
ance of Mr. P. F. Ropell.
The Ruby Chief vein traverses a bedded series of
coarse sandstone and shale belonging to the Ruby
formation of the Upper Cretaceous. The vein oc-
cupies a fault-fracture, as was indicated by a break in
the continuity of a layer of shale seen underground.
The strike is northeast-southwest, while the dip,
northwestward, departs only slightly from the ver-
tical. The accompanying sketch. Fig. 12, gives a
I
[i
1
io8 ACROSS THE SAN JUAN MOUNTAINS
1:1
t I
.■,, ij^i
'^.h
i i <
r ■ ! . -, ■ f ■ •
! ' 1
f f
i'ii
. a
\
M
iv
h
typical section of the lode. In the foot-wall there is
a band of shale. From -,^ to B is a laminated casing
of sandstone seamed with veinlets of quartz, which
exhibits comb structure. B C is a 6 to 8-inch vein of
white quartz, streaked with arsenical pyrite, or mis-
pickel. This is the best ore. It usually carries ruby
silver (proustite) and brittle silver (stephanite).
Selected ore contains 65 to 100 oz. silver, and from
10 dwt. to one ounce of gold, per ton. This vein or
'leader,' B C, is usually characterized by a defined
streak of pyrite, accompanied by zinc-blende, which
speckles the quartz in lines parallel to the walls of the
vein. C to D is mottled, obscurely brecciated coun-
try, with quartz surrounding the fragments of sand-
stone, and impregnated with arsenical pyrite. D to £
is an outer band of obviously brecciated sandstone
containing but little evidence of mineralization. The
crystalline quartz, lining cavities or 'vugs,' is a
marked feature of the lode, and especially of the inde-
pendent quartz-veins that occur in the outer country
alongside of the main vein. The quartz incrusting
the brecciated sandstone within the lode, appears
banded, due to the contrast between layers of quartz
and mispickel. Rhodochrosite was seen in a few
specimens. Mr. Ropell informed me that the best ore
had been obtained from the vein at the horizon where
it traversed the conglomerate beds, which form an
integral portion of the Ruby formation. To these
notes may be added the fact that porphyrite occurs
in the vicinity. Mr. S. F. Emmons has noted that the
THE RUBY CHIEF VEIN
109
J
:v:-:
'tv../'
» m
■"••■v#int%r-.2'/;i^ - r'-\'
•:••. •.^!^\:i'::i'.>^UM^M■■••■••'•
;i;-
Fig. 12.
ii
■ i
i
I ! '
.'VJ ' i^L
1 1
1]
ill 1'^^
no ACROSS THE SAN JUAN MOUNTAINS
porphyrite occurs apparently as an intrusive sheet fol-
lowing the bedding of these sedimentary rocks, al-
though the compound fracturing associated with the
vein-structure "often gives it the appearance of a dike
within the mineralized zone."^'
Leaving Irwin, we retraced our steps for a mile
and crossed the shoulder of Ohio peak at Kebler pass,
named after the president of the Colorado Fuel &
Iron Company. The winding road was followed
through a pine forest until, on the northwestern slope
of the ridge, it descended abruptly into a narrow
ravine. To ride over a deserted mountain road and
then to come suddenly into full view of a compact
little mining settlement is a sensation which does
much to break the monotony of cross-country riding.
This was Floresta, boasting the only anthracite mine
west of Pennsylvania. The old anthracite min*^,
known as Smith's, near Crested Butte, has Le>.n
worked out, and the new anthracite region, tributary
to Paonia, now being prospected between the Gun-
nison river and the Anthracite range, is yet in an
immature stage of develc^iment.
A note on the Smith anthracite mine will be
proper here. It was located 21 years ago, and opened
in 1882 by George Holt, now of Chicago, Howard F.
Smith, now of Elkhart, Indiana, and Dr. William A.
Bell, of Colorado Springs. They erected a breaker,
installed the requisite machinery and operated it for
" Anthracite-Crested Butte Folio. United States Geological Survey.
'Description of the Elk Mountains,' by S. F. Emmons.
ANTHRACITE MINES
III
several years, until it was acquired by the White
Breast Fuel Company, in which Messrs. J. n. and J.
T. Kebler were interested. Shortly afterward it was
acquired by the Colorado Fuel & Iron Company,
which has since held and .steadily worked the mine
until April, 1903, when it was finally abandoned as
worked out.
The vein averaged from three to four feet in
thickness, and the coal was of excellent quality. An
approximate production of 5,000 tons per month was
maintained. A spur of the Denver & Rio Grande
Railroad from Crested Butte connected with the
breaker. The incline from the mine to the breaker is
1,800 feet long, with a pitch of 45°; it is the longest
and steepest in the State. The gravity system was
employed.
1 \ \ \
Upturned Strata of the West Slope of the Elk Mol'nt ains.
The light-sh?-' " stratum, Jura-Trias ; that to the right of it. Carbon-
iferous ; to i..^ left, Cretaceous. From Hayden's Report of 1874.
Craftei 1$
m
ii
T!l!', ( OAI MINE AT FI.ORESTA- )\V ANT!iR.\-
Ciri. IS i<)RMED— METHODS OF MIMING— iFfE
RPF.iKEF^^V PANORAMIC VIEW.
^"l^C^ "^'^SiK ^^^ '^"^^ ■'^*^^'" ^^ Floresta is
'."^ t^ T^^i'-'nAmW' three teet thick, and (lii»s north
'It an angle of about 20°. It lies
with the iiillslope, the ravine
i having cut into tlie seam so as
to give a line ot nitcrop on both
sides. Tlie agency that was
chiefly instrumental in the de-
velopment of anthracite from bituminous oal is
indicated by the porphyrite, Jiich appears in the
form of dikes in thi railroad < iittin^ and is clearly to
be seen capping the lillside. The coal now being
exploited occurs at a geolog.-^' 1 horizon which is 1 15
feet above the bast- of the I-aransie formation, belong-
ing to the Cretaceous. There is also another, poo ^r
seam, one hundred feet higher. These coal leasures
are covered by a sheet of porphyrite, whicl xtend
for more than a mile aloiit^ the north slf : oi'
Anthracite range, the name of the muc i senai 4
ridge behind the mine. The metamorpi effect o:
the p' rphyrite on the coal is readily apparent; where
the met imorphisni of the sedimentaries is li ist, non-
coking uitumin jus coals ; e found; where i meta-
\
i
ill Mi
ill
E
H-^fl
i \- 1
I
H n
1^: J
w fl
u I
|i»;ffl
i\<:
1
V
THE FLORESTA MINE
"3
morphism has been present, but not severe, the coking
coals occur; and in regions of intense local meta-
morphism the coal has been changed to anthracite.
It has also been observed" that a dike cutting across
a coal seam affects its chemical and physical com-
position for a short distance only, but an intrusive
sheet will affect it for a greater distance and over an
area commensurate with the extent of the eruptive
itself.
The output of the mine at the time of our visit
was 100 to 125 tons per day. The manager, Mr.
Thomas McLaughlin, to whom we were indebted for
man^ courtesies, informed me that there is much
difficulty in keeping miners at Floresta, because the
mine is not in operation, on account of snow, for more
than half the year, which prevents men with families
from going there. Moreover, the narrowness of the
seam and the conditions of working are such that
only the most experienced miners can earn a good
living. The work is much more arduous than that
of ordinary lode-mining, because of the cramped
space and the subsequent disposal of the output.
Owing to the slight dip of the seam, it is difficult to
handle ^ht coal underground; the chutes that carry
the product of the face to the entry are made of No.
16 steel sheets, 3 feet wide, laid on the foot-wall, and
nailed onto sides made of 2 by 6-inch scantling. When
in constant use the angle of inclination is sufficient
"George H. Eldridge, Anthracite-Crested Butte Folio. United States
Oeological Survey.
J
114 ACROSS THE SAN JUAN MOUNTAINS
II
1^
M : I
', \.\i
^1,
li
to keep the chute clear, but if the steel lining becomes
at all rusty, th^ slope proves inadequate for the auto-
matic descent of the coal, and the miner jumps into
the chute and toboggans down the incline, pushing
the coal before him with his feet. The men jet 90
cents for 2,600 pounds, of which it is estimated that
2,000 pounds is clean coal, the balance going over
the culm heap. Wages, as I got them from a scrutiny
of the pay-rolls, averaged $4.25 per day, with about
30 men at work. The men are largely Austrians;
scarcely one-half of the miners speak English.
In the mine we found that pillars to support the
roof were left 15 feet wide, while the rooms or stopes
were 25 feet across. The drilling is done with ma-
chine-augers, the hole being begun with a 2^-inch
bit, and finished with a l>4-inch. Holes are made
from 4 to 6 feet deep. Coarse black powder is used;
it costs the miners $3 per keg of 25 pounds. The
product of the mine is sent to the breaker, which has
a capacity of 600 tons per day. Five si •■? are made.
The coal from the tipple goes over two sets of screen-
bars, the fine passing direct to liie picking-tables and
the lump to the breaking-rolls. These are toothed
rolls of the usual type. Then follow revolving
screen.'. The culm is hand-picked as it runs down
the chutes. These chutes for slate-pitking are
double. Each picker (boys and old or crippled
miners) draws past him just as much coal as he can
thoroughly clean, so that the coal is handl d once
only.
THE FLORESTA MINE
"5
6
The upper landing is 10,175 feet above sea-level.
This makes Floresta the highest coal mine in the
United States, if not, indeed, the highest in operation
■ n\
^ ♦**•/♦
•• ♦ ♦ * »
-_-=^ ■ ■ ' A •*.* , X ♦ ♦ tJ-^— r^^" • . • • .
: •■.•••••N.-V.- .V*"-^*
•.•.•.■•■•. • ../♦ ♦ ♦ ♦ ♦
Fio. 13.
anywhere. An average analysis of the anthracite
shows: „ „
Per Cent.
Fixed carbon 37.51
Volatile combustible 7.62
Moisture qj^
Ash .'."." 4;is
The roof of the seam is a 30-foot bed of sand-
stone; the floor is in shale. Along the railroad grade
HI
I
r
#
^(^
1
f <
> ■ J
■' -1
ii6 ACROSS THE SAN JUAN MOUNTAINS
A MAGNIFICENT VIEW
"7
9S
o
a .
Ut/1
•<
£■3
II
< «
Li ♦^
o
there are afforded several good sections of the sedi-
mentary rocks enclosing the coal, where they are
intruded by porphyrite. A typical section (Fig. 13)
exhibits a dike, evidently a porphyrite containing
large distinct crystals of feldspar. The bed of shale
traversed by the dike is hardened near the por-
phyrite, and otherwise altered into a dark massive
rock. Fragments of shale are included within the
dike. The joints in the sedimentaries cross the dike
clearly, and are, therefore, later than the intrusion of
the latter. There is no distinct parting or wall be-
tween the sedimentaries and the eruptive.
On the railroad grade, and about a mile from
Floresta Itself, a promontory of rock gives a mag-
nificent view of the Anthracite and Ruby ranges. To
the left are dark pine woods sloping from Ohio peak
with an inclination that reproduces the dip of the
porphyrite flow and the coal-beds underneath; in the
middle distance, and contrasting with the dark array
of pines, are brilliantly tinted foothills whose rounded
contour indicates the softer sandstones of the Cre-
taceous. Beyond these rises the abrupt mass of Mt.
Beckwith, built of porphyrite. Above the northern
horizon is Gothic Mountain; to the right, and com-
ing down to meet the other half of the picture,
is the red Ruby range with its serrated comb of dikes,
which can be seen extending in jagged line down to
the valley itself, through which a trout-stream winds
in and out until it is hidden by the precipitous face of
'..'.»
ii8 ACROSS THE SAN JUAN MOUNTAINS
Mt. Marcellina, a dome-shaped laccolith" of por-
phyritic diorite. Far off, palpitating amid the haze
of forest fires, are ranks of distant hills whose purple
The Laccolith of Mt. Marceluna.
After Whitman Cross.
forms are faintly silhouetted against the flawless blue
of a Colorado sky.
" A 'laccolith' is a body of intrusive lava. It does not spread in dikes
or sheets, but gathers into a mass or core, wrhich lifts the overlying strata.
Dr-
ize
pie
(Di)a:pltr \9
OVER THE OHIO PASS -AT GUNNISON AGA .
FISHY YARNS-THE RIVER PORTALS-POETRY AN >
GEOLOGY.
^\
15
lue
likes
rata.
HAVING F'-^-.jta the next
morning, September 16, we
crossed the Ohio pass, on our re-
turn to Gunnison, by a road dif-
ferent to that of our previous
journey, which had now taken
us around a group of three
mountnin peaks. Mt. Wheat-
stone, Mt. Axtell, and Mt. Carbon, and from the
watershed of the Slate river to that of Ohio
creek, both tributaries of the Gunnison, into
which they merge a little to the north of the
town itself. Ohio pass, 10,033 feet above sea-
level, is similar to other mountain crossings; there
is a defunct sawmill with an untidy heap of saw-
dust; an abandoned railroad grade, as though en-
gineering skill had failed of breath; a scattering of
pines, the straggling procession representing the sur-
vivors of those serried ranks that came up the moun-
tain-side in proud array until they encountered an
invisible bar to further advance — the 'timber line'
which, like the shore of an ancient sea, belt? all the
mountains and marks the upward limit of the condi-
tions favorable to forest growth.
i
i I
120 ACROSS THE SaN JUAN MOUNTAINS
We passed Carbon and Castleton, two coal
camps, with all the hideousness that belongs to such
settlements ; then a short stay, pleasant for man and
horse alike, at a roadside ranch, prepared us for a long
canter over the wide dusty road, which finally, but
we could never tell when, brought us into the un-
limited city of Gunnison.
That night at Gunnison we heard the fishermen's
tales. It is a great resort for the manipulators of
rod and line. It is also a mining centre for the sur-
rounding hill-country, so that there is no lack of
fishy yarns. The unwary will hear of mountains of
iron and acres of gold ore; but behind the exaggera-
tion there is the fact that the Gunnison country, with
the Elk mountains to the north and the granite foot-
hills that lead to the San Juan ranges, to the south,
is extremely rich in a variety of mineral wealth —
coal, iron, gold, and silver — which would have under-
gone more substantial exploitation if the windy
breath of a premature boom had not blighted it in the
infancy of its development.
On September 17 we rode from Gunnison to
Gate View. The road follows the Gunnison until it
crosses the river at lola, the shipping point of the
Vulcan district. Takin;,- a cross-country trail, we
filed through the sage-brush covering monotonous
low hills, the remnants of granite mountains that
had yielded to the leveling hand of Time. ^encer
and Dubois, two mining camps, were founc- ."'Imost
desiited. Then, surmounting a ridge, we saw again
151
•f
GATE VIEW
lai
the splendor of the San Juan ranges and the pleasant
valley of the Lake Fork. After weary miles of sage-
brush hillocks it was singularly refreshing to look
upon a landscape through the diversified beauty of
which the modifying influence of geological structure
could be plainly discerned. At Gate View we passed
a night. The name is given to a ranch and railroad
section-house near the natural gateway of the Lake
Fork, which flows through a gap cut in the andesite.
A tongue of this eruptive crosses the broad valley;
the river has cut its way through; high, nearly ver-
tical, cliffs arise on either side; then steep debris
slopes, making a broad V, at the bottom of which the
road, the railroad, and the river jostle each other for
passage ; this framed a view of hills rich in the gold
and russet of the aspens, surmounted by the high
peaks of the San Juan mountains.
Looking through the portals of the river, one is
reminded of Ruskin's question concerning a similar
natural structure : "When did the great spirit of the
river first knock at those adamantine gates? When
did the porter open to it and cast his keys away for-
ever, lapped in whirling sand?" It is a fine simili-
tude; but geology, with less poetic diction, says that
the rock is not adamant to the instrument of erosion
as used by the running stream with patient persistence
through long time, and that no porter was needed to
open the gate; the river found a way by obeying the
laws of its being — gravity, which impelled it to seek
the lowest channel and to deepen that channel
i '
ill
M
122 ACROSS THE SAN JUAN MOUNTAINS
continually, for fear the onlooking hills should fill it
up too fast with their discarded debris.
The road, farther on, alternately crosses flat
stretches of partially cultivated land and descends
into the bed of the stream amid narrow gorges cut
into andesite-breccia and tuflfs, until at the confluence
of Henson creek we rode, under a sharp downpour of
cold rain, into the town of Lake City.
Gothic Mountain. A Trachytic Mass Overlying Cretaceous Rocks.
After James D. Dana.
Vli '
nl
ClHMpt&r 20
LAKE QTY — THE UTE & ULAY MINES — CONCEN-
TRATING MILL — ELECTRICAL DRILLS — ROUGH
HANDLING — NEW MILLS.
E reached Lake City at noon
amid a rainstorm which was re-
markable for the reason that it
was the first bit of bad weather
encountered during twelve days,
ft cleared in the afternoon,
so, leaving our horses to rest, we
walked the seven miles up Hen-
son creek to the Ute & Ulay mines. These have been
the mainstay of Lake City through all the vicissitudes
of the past twenty years. The two veins have been
worked at various times both jointly and separately.
When I was last there the Ulay lode was the chief
source of production; on the present occasion we
found that the Ute vein was affording the principal
stoping ground. This was above the main adit.
The vein is from four to five feet v/ide ; it is a simple
quartz vein conaining argentiferous galena. Iron
pyrite and zinc-blende are present in relatively small
quantity. The lode is essentially an impregnation
following a sheeted band in the andesitic breccia of
the San Juan formation and has the characteristics
already noted at the Camp Bird, Smuggler Union,
124
AC KKSS THE SAN JUAN MOUNTAINS
4l
ipjlf-!i \
' k ! !
Is
^ri ' f'
,1
11
4
and other mines in the same region. Stopes extend,
nearly continuously, for half a mile. The Ute dips
westward ;i ' 63" and is worked in the adjacent Cali-
fornia mine. The Ulay has been worked 700 feet
below Henson creek through old workings, which
were in had repair; a new vertical shaft had just been
started to open up the lower ground on this lode.
The mill reminded me, in its method of treat-
ment, of the old Foxdale mine, in the Isle of Man,
where, however, raff-wheels are used instead of ele-
vators and the plant is spread over a much larger
area. The treatment is simple and well adapted to
the character ( the ore. The mill has a capacity
of 90 to 100 tons per day. The ore goes first to a
rock-breaker (Blake, 9 by 15 in.) and then to three
sets of rol'-i (Allis-Chalmers, 16 by 30 in.), then
through four successive trommels, 36 in. diam. and
7 ft. long, which sizr the crushed ore to 8, 6, 4, and
2y2 millimetres. The coarse, which passes through
the trommels, goes to the jigs, a double-compartment
jig for each trommel. The fine, which escapes from
the last trommel, passes into two hydraulic sizers, the
coarse being sent to jigs, while the fine goes into a
third sizer. The coarse from this last sizer goes to
a jig and the fine runs to the buddies. There are two
plain buddies, 16 ft. diam., and four double-deck bud-
dies, 24 ft. diam., the tailing from which passes into
settling-vats, where the slime is arrested.
The concentrate is dried and mixed by passing
through a heated revolving cylinder. About 1^ per
L«r1
H
ALONG HENSON CREEK
135
cent of moisture is left in the comentrate, in ordrr to
lessen the leakage arising from the bad fooring of
the railroad cars, which wtiuld be a greater source
of loss if ;1ic concentrate were dry enough to run
readily, i .i,- concentrate com tins 58 to 61% lead.
13 to 15 oz. silver and 0.05 to 0.06 oz. gold per ton;
this represent* about 16% in weight of the original
ore and an extraction of about 80% of the lead and
65vi of the silver.
Next day, September 18, saw u.s started on our
final stage, from Lake City to Ouray. The road took
us again past the Ute & Ulay, where we stopped to
get some further data from the millman. As we rode
up Hen.son creek it was pleasant to notice a good
deal of mining activity ; we passed under the Bleichert
tramway of the H«r»den Treasure, past the More mill,
with a Leschen ; . n r nnecting it to an unseen mine
on the pine-clad noi. t.iT --.-ide, and then, just below
Rose's Cabin, the ... uh-m t mnel, with a new mi'' :,
course of construe .-, M-. Philip Newitt. suyir'-^-
tendent of the Henson C ;eek Lead Mines C ni'.;.;,y
as it is officially styled, was kind enough to ;-. us
underground. The lode is the usual sheeted band of
andesite-breccia, carrying four to five feet of quartz,
in which gold, silver, copper, and lead are carried by
copper pyrite, galena, and other less conspicuous
minerals.
This mine afforded an example of the use of
electric drills; the Gardner and Durkee were both in
use and the superintendent expressed himself as dis-
i tl
126 ACROSS THE SAN JUAN MOUNTAINS
kt ,N,
appointed with them; in each case the motor is carried
on a truck and power is transmitted through a flexible
shaft. The practical efficiency of the electric drills
is a subject too large for passing comment, though it
is fair to the inventors to say that the machines suffer
from their unpopularity among miners and the fre-
quent lack of technical skill on the part of the
operator. As a rule the first drill tested in a mine is
handled by an expert provided by the company that
sells the drill; then, results being deemed good by a
manager or director, others are ordered. The drill
company's man and his skilled assistants depart,
leaving a delicate piece of electrical machinery to the
tender mercies of a muscular workman, who starts
with a prejudice against anything new and unfamiliar,
and is apt to be confirmed in his prejudice by his own
inexpert handling of the machine. ' This, of course,
is, in a way, the drawback to all electrical machinery
— it requires workmen who know something about
it — but it is an obstacle that the increasing applica-
tion of electricity will overcome, surely. In the
meantime I unite with others in the hope that the
electric drill will be further improved, because it can
facilitate and cheapen mountain mining to an extra-
ordinary degree.
chapter 21
ROSE'S CABIN — CLIMBING THE RANGE — A SNOW-
STORM—BEAR CREEK — AFTER THE STORM — A
GLORIOUS PICTURE — ARRIVAL AT OURAY — THE
END.
\
OSE'S CABIN, at 10,850 feet,
just above the Bonanza mine-
bu Mings, is a landmark. It was
a stopping place in the old days
of transmontaine travel when
long lines of pack-mules and
horsemen were wont to file up
Henson creek on their way to
Silverton, Rico, and Ouray. We took the right-hand
trail, past the Palmetto mill and along the old grade
to the Frank Hough mine.
As we climbed the range, the snow-mists gath-
ered, and when we finally reached the crest, at 12,850
feet, the mountains were robed in all th; magnificence
of the storm. The cold blast from the canon below
swept up to the summit of the range, driving a chilly
mist, which flung itself fiercely around every crag and
threw great shadows that stalked swiftly across the
darkening slopes. Here and there amid the gloom
a lonely peak c.-ught the light, a Titan head above the
sea of cloud. Thus we saw old Uncompahgre and
the Wetterhorn, besides many another unnamed
»1
128 ACROSS THE SAN JUAN MOUNTAINS
m
*
11
it
crest. While we waited, the hail and snow came
fast, and so, without further delay, we began the slow
descent of the other side, leading and pulling our
shivering horses down the tedious talus slopes.
Soon we reached the warmer air of Bear creek
basin, a spacious amphitheatre near the timber-line,
from which a well-marked trail took us into Bear
creek caiion, a narrow gorge, lined by the most
astounding precipices and picturesque to a degree
that was astonishing even after two weeks of moun-
tain scenery. The andesite-breccia, in nearly level
layers, forms cliffs that sweep from an eerie height of
a thousand feet, and more, down into the hidden bed
of a torrent. The sheeted structure, due to parallel-
ism of nearly vertical fractures, is noticeable, and the
sympathetic structure of the veins is apparent even
at a distance, for their outcrops are clearly visible,
ribbing the rock faces with broken lines cf quartz.
We passed the Yellow Jacket and the Grizzly
Bear mines, huddled under the beetling brows of
breccia cliffs, where, here and there, a cluster of
courageous pines clung hungrily for life, or a solitary
cabin looked calmly over the abyss, or faint trails in
unexpected tracery of line wound in and out of dark
ravines with the veritable unconscious air of gentle-
men without visible means of support.
Our progress, over a trail which was a narrow,
albeit quite safe, ledge between rock and torrent, was
necessarily, with horses, a slow business. At length,
after hours of a continuous descent, which seemed
z
II
^^^^H
fI
til
11
'HI ^
if
^1
jkj£k.«:
STORM ON THE RANGE
129
interminable and gave us a singular feeling of going
right into the depths of the earth, we emerged sud-
denly into full view of the Uncompahgre valley. It is
no exaggeration to say that all four of us, some of
w^hom had made the voyage rotmd th«» world more
than once, were amazed at the grandeur of the great
picture before us. Scattered already to the four
winds, as becomes mining engineetfs,'* we shall, I
believe, always remember titat "polychrome of splen-
dor, an exultation to recall. ' Ruskin would have
rhapsodized over it and Clarence Kmg could have
described it.'*
The storm had swept northward, the sky was
still partly overcast with flying ek)ud, a luminous
atmosphere, pure as interplanetary space, filled the
cafion depths, and from the west the sonlight pierced
the lingering mists with mellow light. We stood on
a narrow promontory. Across the caiion the ter-
raced slopes descended in parklike gradation, re-
splendent with the livery of autumn, and above their
aspen gold \he bsistions of hiue-gray andesite rose
tier after tier in Gothic severity cff line until belted
with the rising mists. Up the valley to the left the
winding thread of the river led to the nyramid of
Mt. Abram, his sentniel he.ad aglow with sunlight,
while farther south rose the Red mountams, shrouded
"One is in Western Australia, another in California. tJw Awii :■; in
Mexico, and the fourth in N'ew York City.
This gives me the iip|>ortiinity of recommending to -fw friends that
most delightful book ot Clarence King, 'Mountaineering m the Sierra
Nevada.'
t'l'-
130 ACROSS THE SAN JUAN MOUNTAINS
in cold vapor that dimmed their volcanic tii
Straight in front and northward, overtopping th
swiftly changing visions of rich coloring and sci
tured line, there gleamed the Mt. SneflFels rant
freshly ennobled by a coronet of snow, with a gr
passion of light glowing about their lordly summ
while in the darkening east there trailed away
gray-winged form, the ghost of wind and rain."
It will seem something of an anti-climax
state that the trail subsequently led us to an intere
mg geological section, where the breccia of t
Eocene period was found resting upon the upturn
edges of pre-Cambrian slates and quartzite, with or
a thin layer of conglomerate, possibly a represem
tive of the Telluride formation, between them \
reached Ouray before dark, having completed a ri
of fully 400 miles.
"For what high end is all this daily boon,
Unseen of man, in sightless silence spent?
Doth lavish Nature vainly importune
The unconscious witness of the firmament?
"Or. is it that the influent God, whose breath
Informs witn glory sea, and shore, and hill,
His mfmite lone rejoicing nourisheth
Upon the bounteous outcome of His will?
— Brunton Sincns.
JNS
:anic tints,
pping these
and sculp-
'els ranges,
^ith a great
y summits,
d away "a
rain."
-climax to
iri interest-
cia of the
e upturned
, with only
•epresenta-
hem. We
sted a ride
J
f^^
m